[leetcode] problem 62 – unique paths

public int (int m, int n) {
    int[][] dp = new int[m][n];

    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            if (i == 0 || j == 0)
                dp[i][j] = 1;
            else
                dp[i][j] = dp[i-1][j] + dp[i][j-1];
        }
    }

    return dp[m-1][n-1];
}