27 Remove Element

Author: int32bit

README.md

@@ -17,6 +17,7 @@
 + [21 Merge Two Sorted Lists](algorithms/MergeTwoSortedLists)
 + [22 Generate Parentheses(递归、搜索)](algorithms/GenerateParentheses)
 + [26 Remove Duplicates from Sorted Array](algorithms/RemoveDuplicatesfromSortedArray)
++ [27 Remove Element](algorithms/RemoveElement)
 + [29 Divide Two Integers(位运算、最小负数绝对值、溢出检测)](algorithms/DivideTwoIntegers)
 + [31 Next Permutation(全排列)](algorithms/NextPermutation)
 + [35 Search Insert Position(二分查找)](algorithms/SearchInsertPosition)

algorithms/RemoveElement/README.md

@@ -0,0 +1,19 @@
+## Remove Element
+
+Given an array and a value, remove all instances of that value in place and return the new length.
+
+The order of elements can be changed. It doesn't matter what you leave beyond the new length.
+
+## Solution
+遍历数组，并逐一原地拷贝不等于key的元素
+```cpp
+int removeElement(int a[], int n, int key)
+{
+	int k = 0;
+	for (int i = 0; i < n; ++i) {
+		if (a[i] != key)
+			a[k++] = a[i];
+	}
+	return k;
+}
+```

algorithms/RemoveElement/solve.c

@@ -0,0 +1,21 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+int removeElement(int a[], int n, int key)
+{
+	int k = 0;
+	for (int i = 0; i < n; ++i) {
+		if (a[i] != key)
+			a[k++] = a[i];
+	}
+	return k;
+}
+int main(int argc, char **argv)
+{
+	int a[] = {1,2,3,2,3,2,1,6,2};
+	int n = removeElement(a, 9, 2);
+	for (int i = 0; i < n; ++i)
+		printf("%d ", a[i]);
+	printf("\n");
+	return 0;
+}