LeetCode-Unique Paths

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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?

解题报告：动态规划的基础题，用一个数组存储到各个点的有多少条路。

如果数组没被存入数字，那就存储，这条路前一点的数字。如果已被存入数字，那就加入这条路前一点的数字。

class Solution {public:   int uniquePaths(int m, int n)  {        int temp[m][n];        for (size_t i = 0; i != m; i++)            for(size_t j = 0; j != n; j++)            temp[i][j] = -1;        temp[0][0] = 1;        for (size_t i = 0; i != m; i++) {            for(size_t j = 0; j != n; j++) {              if(j != n-1) {                if(temp[i][j+1] != -1)                   temp[i][j+1] += temp[i][j];                else                    temp[i][j+1] = temp[i][j];              }              if(i != m-1) {                if(temp[i+1][j] != -1)                    temp[i+1][j] += temp[i][j];                else                    temp[i+1][j] = temp[i][j] ;              }            }         }         return temp[m-1][n-1];    }};

Note: m and n will be at most 100.

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