算法训练营第三十九天|62.不同路径 63. 不同路径 II

Leetcode62.不同路径

class Solution {
public:
    int uniquePaths(int m, int n) {
        vector<vector<int>> dp(m, vector<int>(n));
        for (int i = 0; i < dp.size(); i++) dp[i][0] = 1;
        for (int j = 0; j < dp[0].size(); j++) dp[0][j] = 1;
        for (int i = 1; i < dp.size(); i++){
            for (int j = 1; j < dp[0].size(); j++){
                dp[i][j] = dp[i][j- 1] + dp[i - 1][j];
            }
        }
        return dp[dp.size() - 1][dp[0].size() - 1];
    }
};

Leetcode63. 不同路径 II

dp[i][j] = dp[i - 1][j] + dp[i][j - 1];

dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
这句多打了个等号导致一直过不了，注意注意！

class Solution {
public:
    int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {
        int m = obstacleGrid.size();
        int n = obstacleGrid[0].size();
        vector<vector<int>> dp(m, vector<int>(n, 0));
        for (int i = 0; i < m && obstacleGrid[i][0] == 0; i++) dp[i][0] = 1;
        for (int j = 0; j < n && obstacleGrid[0][j] == 0; j++) dp[0][j] = 1;
        for (int i = 1; i < m; i++){
            for (int j = 1; j < n; j++){
                if (obstacleGrid[i][j] == 1) continue;
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
            }
        }
/*
        for (int i = 0; i < m; i++){
            for (int j = 0; j < n; j++){
                cout << dp[i][j] << endl;
            }
        }
*/
        return dp[m - 1][n - 1];
    }
};

第三十九天打卡，加油！！！