Starting
in the top left corner of a 2
2 grid, and only being able to move to the right and down, there are
exactly 6 routes to the bottom right corner.
How
many such routes are there through a 2020 grid?
题目大意：
从一个22网格的左上角开始，有6条（不允许往回走）通往右下角的路。
对于2020的网格，这样的路有多少条？
// （Problem 15）Lattice paths // Completed on Tue, 11 Feb 2014, 23:58 // Language: VC++2010 // // 版权所有（C）acutus (mail: acutus@126.com) // 博客地址：http://www.cnblogs.com/acutus/ #include<iostream> #include<cmath> using namespace std; long long a[21][21]; int main() { int i; for(i = 0; i < 21; i++) { a[0][i] = 1; a[i][0] = 1; } for (i = 1; i < 21; i++) for (int j = 1; j < 21; j++) a[i][j] = a[i][j-1] + a[i-1][j]; cout<<a[20][20]<<endl; return 0; }
|
Answer: |
137846528820 |
原文：http://www.cnblogs.com/acutus/p/3545233.html