Week1_AnkitaPrasad

Week1/Count Negative Nos/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,14 @@
+class Solution {
+public:
+    int countNegatives(vector<vector<int>>& grid) {
+        int count=0;
+        for(int i=0; i<grid.size(); i++){
+            for(int j=0; j<grid[i].size(); j++){
+                if(grid[i][j]<0){
+                    count++;
+                }
+            }
+        }
+        return count;
+    }
+};

Week1/Count and Say/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,15 @@
+class Solution {
+public:
+    string countAndSay(int n) {
+        if(n==1) {
+            return "1";
+        }
+	auto s = countAndSay(n-1) + ' ';
+	string out;
+	for(auto i{0}, j{0}; i<size(s); ++i)
+		if(s[i] != s[j]) {
+            out= out+ to_string(i-j)+s[i-1], j=i;
+        }
+	return out;
+    }
+};

Week1/Longest Substring wo repeating chars/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,17 @@
+class Solution {
+public:
+    int lengthOfLongestSubstring(string s) {
+         int i=0,j=0,ans=0;
+        set<char> a;
+        while(i<s.size()&&j<s.size()){
+            if(a.find(s[j])==a.end()){
+                a.insert(s[j++]);
+                ans=max(ans,j-i);
+            }
+            else{
+                a.erase(s[i++]);
+            }
+        }
+        return ans;
+    }
+};

Week1/Max Subarray/week1_AnkitaPrasad.cpp

@@ -0,0 +1,12 @@
+class Solution {
+public:
+    int maxSubArray(vector<int>& nums) {
+         int sum = nums[0];
+        int max_sum = nums[0];
+        for (int i=1; i<nums.size(); i++){
+            sum = max(nums[i], sum + nums[i]);
+            max_sum = max(max_sum, sum);
+        }
+        return max_sum;
+    }
+};

Week1/Missing no/Week1_AnkitaPrasad.txt

@@ -0,0 +1,23 @@
+class Solution {
+public:
+    int missingNumber(vector<int>& nums) {
+
+
+        if(nums.size()==0)
+        {
+            return 0;
+        }
+
+        sort(nums.begin(),nums.end());
+
+        for(int i=0;i<nums.size();i++)
+        {
+            if(nums[i]!=i)
+            {
+                return i;
+            }
+        }
+      return nums.size(); 
+    }
+
+};

Week1/Monotonic Array/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,21 @@
+class Solution {
+public:
+    bool isMonotonic(vector<int>& A) {
+        int count1=1,count2=1;
+
+        for(int i=0;i<A.size()-1;i++)
+        {
+            if(A[i]<=A[i+1])
+            {
+                count1++;
+            }
+            if(A[i]>=A[i+1])
+            {
+                count2++;
+            }
+        }
+
+        return count1==A.size() || count2==A.size();
+
+    }
+};

Week1/Move Zeroes/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,14 @@
+class Solution {
+public:
+    void moveZeroes(vector<int>& nums) {
+        int j=0;
+        for(int i=0; i<nums.size(); i++){
+            if(nums[i]!=0){
+                nums[j++]= nums[i];
+            }
+        }
+        for(int i=j; i<nums.size(); i++){
+            nums[i]=0;
+        }
+    }
+};

Week1/Pascal Triangle/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,18 @@
+class Solution {
+public:
+    vector<vector<int>> generate(int numRows) {
+        vector<vector<int>> number;
+        if (!numRows) 
+            return number;
+
+        number.push_back({1});
+
+        for (int i = 1; i < numRows; i++) {
+            vector<int> t(i+1,1);
+            for (int j = 1; j < i; j++)
+                t[j] = number[i-1][j-1] + number[i-1][j];
+            number.push_back(t);
+        }
+        return number; 
+    }
+};

Week1/Pivot Index/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,17 @@
+class Solution {
+public:
+    int pivotIndex(vector<int>& nums) {
+        int tsum=0, l_sum=0;
+        for(int i=0; i<nums.size();i++){
+            tsum=tsum+nums[i];   //getting the whole sum of array
+        }
+        for(int i=0; i<nums.size(); i++){
+            if(i!=0){
+            l_sum=l_sum+nums[i-1];
+            }
+            if(tsum-l_sum-nums[i]==l_sum)
+                return i;
+       }
+       return -1;
+    }
+};

Week1/Product Of Array/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,23 @@
+class Solution {
+public:
+    vector<int> productExceptSelf(vector<int>& nums) {
+        vector<int> ans;
+        if(nums.size()<1){
+            return ans;
+        }
+
+        int product=1;
+        for(int i=0; i<nums.size(); i++){
+            product = product *nums[i];
+            ans.push_back(product);
+        }
+
+        product=1;
+        for(int i=nums.size()-1; i>0; --i){
+            ans[i]= ans[i-1]*product;
+            product=product*nums[i];
+        }
+        ans[0]= product;
+        return ans;
+    }
+};

Week1/Remove Duplicates/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,6 @@
+class Solution {
+public:
+    int removeDuplicates(vector<int>& nums) {
+      return  unique(nums.begin(), nums.end()) - nums.begin();
+    }
+};

Week1/Reverse Only Letters/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,18 @@
+ class Solution {
+public:
+    string reverseOnlyLetters(string s) {
+         vector<char> result;
+        map<int,char> m; 
+        for(int i=0;i<s.size();i++){
+            if(!isalpha(s[i])) m[i]=s[i];
+            else result.push_back(s[i]);
+        }
+        reverse(result.begin(),result.end());
+        for(auto i:m){
+            result.insert(result.begin() +i.first, i.second);
+        }
+        string str(result.begin(), result.end());
+        return str;
+
+    }
+};

Week1/Reverse vowels/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,29 @@
+class Solution {
+public:
+     inline bool isVowel(char ch)
+  {
+    return (
+        ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' ||
+        ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U');
+  }
+
+    string reverseVowels(string s) {
+        int i = 0;
+        int j = s.size()-1;
+        while(i<j){
+            if(isVowel(s[i])){
+                if(isVowel(s[j])){
+                    swap(s[i], s[j]);
+                    i++;
+                    j--;
+                }else{
+                    j--;
+                }
+            }else{
+                i++;
+            }
+        }
+
+        return s;
+    }
+};

Week1/Rotate Array/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,9 @@
+class Solution {
+public:
+    void rotate(vector<int>& nums, int k) {
+      k=k%nums.size(); 
+        reverse(nums.end()-k, nums.end());
+        reverse(nums.begin(), nums.end()-k);
+       reverse(nums.begin(), nums.end());
+    }
+};

Week1/Spiral Matrix/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,43 @@
+class Solution {
+public:
+    vector<int> spiralOrder(vector<vector<int>>& matrix) {
+        int right =matrix[0].size()-1;
+        int bottom = matrix.size()-1;
+        int left = 0;
+        int top=0;
+        int direction = 0;
+        vector <int> ans;
+        while(top<= bottom && left <= right){
+        if (direction==0){
+            for (int i =left; i<=right;i++){
+                ans.push_back(matrix[top][i]);
+            }
+            top +=1;
+            direction +=1;
+        }
+        else if (direction ==1){
+            for(int i=top; i<=bottom; i++){
+                ans.push_back(matrix[i][right]) ;
+            }
+            direction +=1;
+            right -=1;
+        }
+        else if (direction ==2){
+            for(int i =right; i>=left; i--){
+                ans.push_back(matrix[bottom][i]);
+            }
+            direction +=1;
+            bottom -=1;
+        }
+        else if (direction ==3){
+            for(int i=bottom; i>=top; i--){
+                ans.push_back(matrix[i][left]);
+            }
+            direction =0;
+            left +=1;
+        }
+    }
+
+    return ans; 
+    }
+};

Week1/Target Array/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,12 @@
+class Solution {
+public:
+    vector<int> createTargetArray(vector<int>& nums, vector<int>& index) {
+        vector<int>ans;
+        for(int i=0; i<nums.size(); i++){
+            ans.insert(ans.begin()+index[i], nums[i]);
+        }
+
+        return ans;
+
+    }
+};

Week1/Valid Palindrome/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,21 @@
+class Solution {
+public:
+    bool isPalindrome(string s) {
+        int i=0,j=s.size()-1;
+        while(i<j){
+                 if(!isalnum(s[i])){
+                     i++;
+        }
+                 if(!isalnum(s[j])){
+                     j--;
+                 }
+             if(isalnum(s[i])&&isalnum(s[j])){
+                 if(tolower(s[i])!=tolower(s[j]))
+                     return false;
+                 i++;
+                 j--;
+             }
+        }
+        return true;
+    }
+};

Week1/Week1/Count Negative Nos/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,14 @@
+class Solution {
+public:
+    int countNegatives(vector<vector<int>>& grid) {
+        int count=0;
+        for(int i=0; i<grid.size(); i++){
+            for(int j=0; j<grid[i].size(); j++){
+                if(grid[i][j]<0){
+                    count++;
+                }
+            }
+        }
+        return count;
+    }
+};

Week1/Week1/Count Negative Nos/week1.md

@@ -0,0 +1 @@
+Enter Week1 codes

Week1/Week1/Count and Say/Week1_AnkitaPrasad.cpp

@@ -0,0 +1,15 @@
+class Solution {
+public:
+    string countAndSay(int n) {
+        if(n==1) {
+            return "1";
+        }
+	auto s = countAndSay(n-1) + ' ';
+	string out;
+	for(auto i{0}, j{0}; i<size(s); ++i)
+		if(s[i] != s[j]) {
+            out= out+ to_string(i-j)+s[i-1], j=i;
+        }
+	return out;
+    }
+};

Week1/Week1/Count and Say/week1.md

@@ -0,0 +1 @@
+Enter Week1 codes