halo world ））） uva 10934 droping water

纯思维题目啊。。。。

最关键的是可以测到的楼梯的定义，有可能没用完就已经测到了。

#include <cstdio>unsigned long long d[64],n,m,x,y;int main() {  //freopen("out.txt","w",stdout);  int k;  while(scanf("%lld%lld",&n,&m) == 2 && n)   {for(int i = 1; i < 64; i++) d[i] = i; int cnt = 0;while(++cnt < n) {  x = 1;  for(int i = 1; i < 63; i++) {y = x; x = d[i+1];d[i+1] = y + d[i] + 1;  }}int ans = -1;for(int k = 1; k <= 63; k++) {  if(d[k] >= m) {ans = k; break;}}if(ans < 0) printf("More than 63 trials needed.\n");else printf("%d\n",ans);  }}