UVA - 10334 Ray Through Glasses

题意：在n次的反射后一共有几条线，这里解释的很好点击打开链接

#include <iostream>#include <cstdio>#include <cstring>#include <cmath>using namespace std;const int MAXN = 1005;int n,f[MAXN][MAXN];void init(){   f[1][0] = 1;   f[2][0] = 1;   int a,c = 0;   for (int i = 3; i <= MAXN; i++)       for (int j = 0; j < 250; j++){            a = f[i-1][j] + f[i-2][j] + c;            c = a / 10;            f[i][j] = a % 10;       }}int main(){    init();    while (scanf("%d",&n) != EOF){        n += 2;        int cnt = 250;        while (f[n][cnt] == 0)            cnt--;        for (int i = cnt; i >= 0; i--)            printf("%d",f[n][i]);        printf("\n");    }        return 0;}