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feat: add solutions to lc problems: No.3550,3551 (#4411)
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‎solution/3500-3599/3550.Smallest Index With Digit Sum Equal to Index/README.md

+74-4
Original file line numberDiff line numberDiff line change
@@ -81,32 +81,102 @@ edit_url: https://github.com/doocs/leetcode/edit/main/solution/3500-3599/3550.Sm
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<!-- solution:start -->
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### 方法一
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### 方法一：枚举 + 数位和
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我们可以从下标 $i = 0$ 开始，遍历数组中的每个元素 $x$，计算 $x$ 的数位和 $s$。如果 $s = i$，则返回下标 $i$。如果遍历完所有元素都没有找到满足条件的下标，则返回 -1。
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时间复杂度 $o(n)$，其中 $n$ 是数组的长度。空间复杂度 $o(1)$，只使用了常数级别的额外空间。
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<!-- tabs:start -->
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#### Python3
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```python
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class Solution:
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def smallestIndex(self, nums: List[int]) -> int:
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for i, x in enumerate(nums):
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s = 0
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while x:
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s += x % 10
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x //= 10
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if s == i:
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return i
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return -1
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```
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#### Java
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```java
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class Solution {
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public int smallestIndex(int[] nums) {
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for (int i = 0; i < nums.length; ++i) {
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int s = 0;
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while (nums[i] != 0) {
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s += nums[i] % 10;
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nums[i] /= 10;
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}
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if (s == i) {
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return i;
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}
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}
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return -1;
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}
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}
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```
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#### C++
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```cpp
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class Solution {
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public:
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int smallestIndex(vector<int>& nums) {
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for (int i = 0; i < nums.size(); ++i) {
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int s = 0;
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while (nums[i]) {
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s += nums[i] % 10;
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nums[i] /= 10;
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}
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if (s == i) {
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return i;
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}
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}
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return -1;
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}
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};
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```
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#### Go
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```go
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func smallestIndex(nums []int) int {
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for i, x := range nums {
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s := 0
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for ; x > 0; x /= 10 {
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s += x % 10
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}
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if s == i {
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return i
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}
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}
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return -1
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}
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```
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#### TypeScript
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```ts
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function smallestIndex(nums: number[]): number {
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for (let i = 0; i < nums.length; ++i) {
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let s = 0;
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for (; nums[i] > 0; nums[i] = Math.floor(nums[i] / 10)) {
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s += nums[i] % 10;
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}
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if (s === i) {
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return i;
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}
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}
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return -1;
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}
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```
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<!-- tabs:end -->

‎solution/3500-3599/3550.Smallest Index With Digit Sum Equal to Index/README_EN.md

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@@ -79,32 +79,102 @@ edit_url: https://github.com/doocs/leetcode/edit/main/solution/3500-3599/3550.Sm
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<!-- solution:start -->
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### Solution 1
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### Solution 1: Enumeration + Digit Sum
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We can start from index $i = 0$ and iterate through each element $x$ in the array, calculating the digit sum $s$ of $x$. If $s = i$, return the index $i$. If no such index is found after traversing all elements, return -1.
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The time complexity is $O(n)$, where $n$ is the length of the array. The space complexity is $O(1)$, as only constant extra space is used.
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<!-- tabs:start -->
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#### Python3
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```python
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class Solution:
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def smallestIndex(self, nums: List[int]) -> int:
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for i, x in enumerate(nums):
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s = 0
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while x:
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s += x % 10
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x //= 10
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if s == i:
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return i
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return -1
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```
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#### Java
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```java
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class Solution {
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public int smallestIndex(int[] nums) {
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for (int i = 0; i < nums.length; ++i) {
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int s = 0;
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while (nums[i] != 0) {
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s += nums[i] % 10;
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nums[i] /= 10;
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}
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if (s == i) {
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return i;
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}
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}
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return -1;
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}
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}
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```
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#### C++
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```cpp
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class Solution {
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public:
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int smallestIndex(vector<int>& nums) {
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for (int i = 0; i < nums.size(); ++i) {
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int s = 0;
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while (nums[i]) {
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s += nums[i] % 10;
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nums[i] /= 10;
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}
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if (s == i) {
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return i;
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}
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}
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return -1;
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}
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};
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```
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#### Go
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```go
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func smallestIndex(nums []int) int {
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for i, x := range nums {
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s := 0
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for ; x > 0; x /= 10 {
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s += x % 10
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}
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if s == i {
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return i
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}
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}
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return -1
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}
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```
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#### TypeScript
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```ts
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function smallestIndex(nums: number[]): number {
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for (let i = 0; i < nums.length; ++i) {
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let s = 0;
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for (; nums[i] > 0; nums[i] = Math.floor(nums[i] / 10)) {
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s += nums[i] % 10;
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}
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if (s === i) {
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return i;
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}
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}
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return -1;
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}
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```
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<!-- tabs:end -->

‎solution/3500-3599/3550.Smallest Index With Digit Sum Equal to Index/Solution.cpp

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@@ -0,0 +1,16 @@
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class Solution {
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public:
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int smallestIndex(vector<int>& nums) {
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for (int i = 0; i < nums.size(); ++i) {
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int s = 0;
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while (nums[i]) {
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s += nums[i] % 10;
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nums[i] /= 10;
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}
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if (s == i) {
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return i;
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}
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}
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return -1;
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}
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};

‎solution/3500-3599/3550.Smallest Index With Digit Sum Equal to Index/Solution.go

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,12 @@
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func smallestIndex(nums []int) int {
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for i, x := range nums {
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s := 0
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for ; x > 0; x /= 10 {
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s += x % 10
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}
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if s == i {
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return i
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}
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}
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return -1
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}

‎solution/3500-3599/3550.Smallest Index With Digit Sum Equal to Index/Solution.java

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@@ -0,0 +1,15 @@
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class Solution {
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public int smallestIndex(int[] nums) {
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for (int i = 0; i < nums.length; ++i) {
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int s = 0;
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while (nums[i] != 0) {
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s += nums[i] % 10;
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nums[i] /= 10;
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}
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if (s == i) {
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return i;
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}
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}
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return -1;
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}
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}

‎solution/3500-3599/3550.Smallest Index With Digit Sum Equal to Index/Solution.py

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@@ -0,0 +1,10 @@
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class Solution:
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def smallestIndex(self, nums: List[int]) -> int:
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for i, x in enumerate(nums):
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s = 0
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while x:
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s += x % 10
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x //= 10
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if s == i:
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return i
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return -1

‎solution/3500-3599/3550.Smallest Index With Digit Sum Equal to Index/Solution.ts

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@@ -0,0 +1,12 @@
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function smallestIndex(nums: number[]): number {
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for (let i = 0; i < nums.length; ++i) {
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let s = 0;
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for (; nums[i] > 0; nums[i] = Math.floor(nums[i] / 10)) {
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s += nums[i] % 10;
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}
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if (s === i) {
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return i;
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}
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}
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return -1;
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}

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