Leetcode Sols

56.cpp

@@ -0,0 +1,21 @@
+class Solution {
+public:
+    vector<vector<int>> merge(vector<vector<int>>& intervals) {
+        vector<int>arr(2);
+        vector<vector<int>>ans;
+        if(intervals.size()==0) return ans;
+        sort(intervals.begin(),intervals.end());
+        arr[0]=intervals[0][0];arr[1]=intervals[0][1];
+        for(int i=1;i<intervals.size();i++)
+        {   if(arr[1]>=intervals[i][0])
+                arr[1]=max(intervals[i][1],arr[1]);
+            else
+            {   ans.push_back({arr[0],arr[1]});
+                arr[0]=intervals[i][0];
+                arr[1]=intervals[i][1];  
+            }
+        }
+        ans.push_back({arr[0],arr[1]});
+        return ans;
+    }
+};

59.cpp

@@ -0,0 +1,35 @@
+class Solution {
+public:
+
+    vector<vector<int>> generateMatrix(int n) {
+        vector<vector<int>> matrix;
+        matrix.resize(n, std::vector<int>(n, -1));
+
+        int top = 0;
+        int bottom = n-1;
+        int left = 0;
+        int right = n-1;
+        int val = 1;
+        while (left<=right) {
+
+            for (int i = left;i<=right;i++) {
+                matrix[left][i] = val++;
+            }
+            top++;
+
+            for (int i = top;i<=bottom;i++) {
+                matrix[i][right] = val++;
+            }
+            right--;
+            for (int i = right;i>=left;i--) {
+                matrix[bottom][i] = val++;
+            }
+            bottom--;
+            for (int i = bottom;i>=top;i--) {
+                matrix[i][left] = val++;
+            }
+            left++;
+        }
+        return matrix;
+    }
+};

60.cpp

@@ -0,0 +1,24 @@
+class Solution {
+public:
+    string getPermutation(int n, int k) {
+        string st(n,'0');
+        int fact=1;
+        for(int i=1;i<=n;i++){
+            fact*=i;
+            st[i-1]+=(i);
+        }
+        for(int i=0;i<n;i++){
+            int block_num=fact/(n-i);
+            fact/=(n-i);
+            int first_index=i+(k-1)/(block_num);
+            char c=st[first_index];
+            k=k-(((k-1)/(block_num))*(block_num));
+            for(int j=first_index;j>=i+1;j--){
+                st[j]=st[j-1];
+            }
+            st[i]=c;
+            cout<<st<<" "<<k<<" ";
+        }
+        return st;
+    }
+};