public class Solution {public int uniquePaths(int m, int n) {

if (m <= 1 || n <= 1)

return 1;

int[][] dp = new int[m][n];

for (int i = m - 1; i >= 0; i--) {

for (int j = n - 1; j >= 0; j--) {

if (i == m - 1 || j == n - 1) {

dp[i][j] = 1;

}

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

}

}

return dp[0][0];

}

}