leetcode [62] Unique Paths

class Solution {
public:
    void dfs(int m,int n,int x,int y,int&count){
        if(x>=m||x<0||y<0||y>=n) return;
        if(x==m-1&&y==n-1) count++;
        dfs(m,n,x+1,y,count);
        dfs(m,n,x,y+1,count);
    }
    int uniquePaths(int m, int n) {
        int x=0,y=0,count=0;
        dfs(m,n,x,y,count);
        return count;
    }
};

class Solution {
private:
    int dp[105][105];
public:
    int uniquePaths(int m, int n) {
        for(int i=0;i<m;i++) dp[i][0]=1;
        for(int j=0;j<n;j++) dp[0][j]=1;
        for(int i=1;i<m;i++){
            for(int j=1;j<n;j++){
                dp[i][j]=dp[i-1][j]+dp[i][j-1];
            }
        }
        return dp[m-1][n-1];
    }
};