Day 58 by admin

Day 58/Bulb Switcher_Leetcode/Bulb_Switcher.cpp

@@ -0,0 +1,6 @@
+class Solution {
+public:
+    int bulbSwitch(int n) {
+        return sqrt(n);
+    }
+};

Day 58/Easy Task_GFG/Easy_Task.cpp

@@ -0,0 +1,102 @@
+class Solution{
+public:
+    vector<char> easyTask(int n,string s,int q,vector<vector<string>> &queries){
+        vector<vector<int>> tree(4 * n, vector<int> (26));
+
+        function<void(int, int, int)> build = [&](int node, int low, int high){
+            if(low == high){
+                vector<int> f(26, 0);
+                ++f[s[low - 1] - 'a'];
+                tree[node] = f;
+                return;
+            }
+
+            int mid = low + (high - low) / 2;
+            build(2 * node, low, mid);
+            build(2 * node + 1, mid + 1, high);
+
+            for(int i = 0; i < 26; i++)
+                tree[node][i] = tree[2 * node][i] + tree[2 * node + 1][i];
+        };
+
+        function<void(int, int, int, int, int, int)> update = [&](int node, int low, int high, int rangelow, int rangehigh, char dx){
+            if(low > rangehigh or high < rangelow)
+                return;
+
+            if(low >= rangelow and high <= rangehigh){
+                vector<int> f(26, 0);
+                ++f[dx - 'a'];
+                tree[node] = f;
+
+                return;
+            }
+
+            int mid = low + (high - low) / 2;
+
+            update(2 * node, low, mid, rangelow, rangehigh, dx);
+            update(2 * node + 1, mid + 1, high, rangelow, rangehigh, dx);
+
+            for(int i = 0; i < 26; i++)
+                tree[node][i] = tree[2 * node][i] + tree[2 * node + 1][i];
+        };
+
+        function<vector<int>(int, int, int, int, int)> query = [&](int node, int low, int high, int rangelow, int rangehigh) -> vector<int> {
+            vector<int> f(26, 0);
+
+            if(low > rangehigh or high < rangelow)
+                return f;
+
+            if(low >= rangelow and high <= rangehigh)
+                return tree[node];
+
+            int mid = low + (high - low) / 2;
+
+            vector<int> x = query(2 * node, low, mid, rangelow, rangehigh);
+            vector<int> y = query(2 * node + 1, mid + 1, high, rangelow, rangehigh);
+
+            for(int i = 0; i < 26; i++)
+                f[i] = x[i] + y[i];
+
+            return f;
+        };
+
+        build(1, 1, n);
+
+        vector<char> ans;
+
+        for(int i = 0; i < q; i++){
+            int ch = stoi(queries[i][0]);
+
+            if(ch == 1){
+                int index = stoi(queries[i][1]);
+                ++index;
+
+                char c = queries[i][2][0];
+
+                update(1, 1, n, index, index, c);
+            }
+            else{
+                int l, r, k;
+                l = stoi(queries[i][1]);
+                r = stoi(queries[i][2]);
+                k = stoi(queries[i][3]);
+
+                ++l; ++r;
+
+                vector<int> f = query(1, 1, n, l, r);
+
+                int count = 0;
+                for(int i = 25; i > -1; i--){
+                    count += f[i];
+
+                    if(count >= k){
+                        ans.push_back((char)(i + 'a'));
+                        break;
+                    }
+                }
+            }
+        }
+
+        return ans;
+    }
+};