Merge pull request #14 from amajaying/amajaying-changed

Added 4 new leetcode Medium Question C++

Author: Jayanti2919

LeetCode Questions/C++/1. Problems/13-roman-to-integer.cpp

@@ -0,0 +1,32 @@
+class Solution {
+
+private: 
+    int indexOf(char c, vector<char> sym){
+        for(int i=0; i<sym.size(); i++){
+            if(sym[i]==c)
+                return i;
+        }
+        return -1;    
+    }
+public:
+    int romanToInt(string s) {        
+        vector<char> sym{'I','V','X','L','C','D','M'};
+        vector<int> val{1,5,10,50,100,500,1000};
+        
+        int ans = 0;
+        int n = s.length();
+        for(int i=0; i<n-1; i++){
+            int x = indexOf(s[i], sym);
+            int y = indexOf(s[i+1], sym);
+            if(val[x]<val[y])
+                ans-=val[x];
+            else
+                ans+=val[x];
+
+        }
+        int x = indexOf(s[n-1], sym);
+        ans+=val[x];
+        
+        return ans;
+    }
+};

LeetCode Questions/C++/1. Problems/658-find-k-closest-elements.cpp

@@ -0,0 +1,19 @@
+class Solution {
+public:
+    vector<int> findClosestElements(vector<int>& arr, int k, int x) {
+        vector<int> ans;
+        int s = 0; 
+        int e= arr.size()-1;
+        while(e-s>=k){
+            if(x-arr[s]<=arr[e]-x)
+                e--;
+            else
+                s++;
+        }
+        
+        for(int i=s; i<=e; i++){
+            ans.push_back(arr[i]);
+        }
+        return ans;
+    }
+};

LeetCode Questions/C++/1. Problems/66-plus-one.cpp

@@ -0,0 +1,19 @@
+class Solution {
+public:
+    vector<int> plusOne(vector<int>& digits) {
+        int n = digits.size() - 1;
+      
+        for (int i = n; i >= 0; --i){
+            if (digits[i] == 9) {  
+                digits[i] = 0;
+            } 
+            else {  
+                digits[i] += 1;
+                return digits;
+            }
+        }
+        digits.push_back(0);
+        digits[0] = 1;
+        return digits;
+    }
+};

LeetCode Questions/C++/1. Problems/75-sort-colors.cpp

@@ -0,0 +1,31 @@
+class Solution {
+public:
+    void sortColors(vector<int>& nums) {
+        int cn0,cn1,cn2;
+        cn0=cn1=cn2=0;
+        
+        for(int i=0; i<nums.size(); i++){
+            if(nums[i]==0)
+                cn0++;
+            else if(nums[i]==1)
+                cn1++;
+            else
+                cn2++;
+        }
+        int k = 0;
+        for(int i=0; i<cn0; i++){
+            nums[k]=0;
+            k++;
+        }
+        
+        for(int i=0; i<cn1; i++){
+            nums[k]=1;
+            k++;
+        }
+        
+        for(int i=0; i<cn2; i++){
+            nums[k]=2;
+            k++;
+        }
+    }
+};