Merge pull request doocs#239 from hoooga/master

add cpp solutions for weekly contest 165 problems (1275-1278)

Author: yanglbme

solution/1275.Find Winner on a Tic Tac Toe Game/Solution.cpp

@@ -0,0 +1,30 @@
+class Solution {
+    bool checkWin(vector<vector<char>>& board, bool moveA) {
+        char symbol = (moveA ? 'X' : 'O');
+        for (int i = 0; i < 3; i++)
+            if (board[i][0] == symbol && board[i][0] == board[i][1] && board[i][0] == board[i][2]) 
+                return true;
+        for (int i = 0; i < 3; i++)
+            if (board[0][i] == symbol && board[0][i] == board[1][i] && board[0][i] == board[2][i])
+                return true;
+        if (board[0][0] == symbol && board[1][1] == symbol && board[2][2] == symbol)
+            return true;
+        if (board[0][2] == symbol && board[1][1] == symbol && board[2][0] == symbol)
+            return true;
+        return false;
+    }
+public:
+    string tictactoe(vector<vector<int>>& moves) {
+        vector<vector<char>> board(3, vector<char>(3, ' '));
+        bool moveA = true;
+        for (auto &v : moves) {
+            board[v[0]][v[1]] = (moveA ? 'X' : 'O');
+            if (checkWin(board, moveA))
+                return (moveA ? "A" : "B");
+            moveA = !moveA;
+        }
+        if (moves.size() == 9)
+            return "Draw";
+        return "Pending";
+    }
+};

solution/1276.Number of Burgers with No Waste of Ingredients/Solution.cpp

@@ -0,0 +1,13 @@
+class Solution {
+public:
+    vector<int> numOfBurgers(int tomatoSlices, int cheeseSlices) {
+        int x = (tomatoSlices - 2*cheeseSlices);
+        if (x < 0 || x % 2 == 1)
+            return {};
+        x /= 2;
+        int y = cheeseSlices - x;
+        if (y < 0)
+            return {};
+        return {x, y};
+    }
+};

solution/1277.Count Squre Submatrices with All Ones/Solution.cpp

@@ -0,0 +1,28 @@
+class Solution {
+public:
+    int countSquares(vector<vector<int>>& matrix) {
+        int m = matrix.size(), n = matrix[0].size();
+        vector<vector<int>> dp = matrix;
+        for (int i = 0; i < m; i ++) {
+            for (int j = 0; j < n; j++) {
+                if (dp[i][j] && i > 0 && j > 0) {
+                    int edge = min(dp[i][j-1], dp[i-1][j]);
+                    if (edge > 0) {
+                        if (matrix[i-edge][j-edge]) {
+                            dp[i][j] = edge + 1;
+                        } else {
+                            dp[i][j] = edge;
+                        }
+                    } 
+                }
+            }
+        }
+        int ans = 0;
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                ans += dp[i][j];
+            }
+        }
+        return ans;
+    }
+};

solution/1278.Palindrome Partitioning III/Solution.cpp

@@ -0,0 +1,32 @@
+class Solution {
+public:
+    int palindromePartition(string s, int k) {
+        int len = s.length();
+        // cost[i][j] = min #changes needed to turn (s[i],...,s[i+j]) into a palindrome
+        vector<vector<int>> cost(len, vector<int>(len)); 
+        for (int i = 0; i < len; i++) {
+            for (int j = i; j < len; j++) {
+                int begin = i, end = j, cnt = 0;
+                while(begin < end) {
+                    if (s[begin] != s[end])
+                        cnt++;
+                    begin ++, end--;
+                }
+                cost[i][j-i] = cnt;
+            }
+        }
+        // dp[i][j] = min #changes needed to split (s[i],...,s[len]) into j+1 palindromes
+        vector<vector<int>> dp(len, vector<int>(k, INT_MAX));
+        for (int i = 0; i < len; i++) {
+            dp[i][0] = cost[i][len-1-i];
+        }
+        for (int kk = 1; kk < k; kk++) {
+            for (int i = 0; i < len; i++) {
+                for (int j = i+1; j+kk-1 < len; j++) {
+                    dp[i][kk] = min(dp[i][kk], dp[j][kk-1] + cost[i][j-i-1]);
+                }
+            }
+        }
+        return dp[0][k-1];
+    }
+};