A robot is located at the top-left corner of a m x n grid (marked ‘Start‘ in the diagram below).
The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked ‘Finish‘ in the diagram below).
How many possible unique paths are there?
Above is a 3 x 7 grid. How many possible unique paths are there?
Note: m and n will be at most 100.
使用DP的思想，逐行计算。public int uniquePaths(int m, int n) { if (m == 0 || n == 0) { return 0; } int[][] num = new int[m][n]; for (int i = 0; i < m; i++) { for (int j = 0; j < n; j++) { if (i == 0 || j == 0) { num[i][j] = 1; } else { num[i][j] = num[i - 1][j] + num[i][j - 1]; } } } return num[m - 1][n - 1]; }
原文：http://blog.csdn.net/u010378705/article/details/29829903