leetcode_62题——Unique Paths （动态规划）

Unique Paths

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Question Solution

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.

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Array Dynamic Programming

这道题比较简单，就是采用动态规划的做法，需要维护一个路径个数的数组，从靠近终点的点开始往前算起就好了

#include<iostream>
#include <vector>
using namespace std;
#define MAXSIZE 110
int uniquePaths(int m, int n) {
	int ary1[MAXSIZE][MAXSIZE];
	ary1[m][n]=1;
	for(int i=m;i>=1;i--)
		for(int j=n;j>=1;j--)
		{
			if(i==m||j==n)
				ary1[i][j]=1;
			else
				ary1[i][j]=ary1[i+1][j]+ary1[i][j+1];
		}
		return ary1[1][1];
}

int main()
{
}