[UVa] 10446 The Marriage Interview.cpp

#include <cstdio>
using namespace std;
typedef unsigned long long int ullt;

ullt C[61][61]={0};
ullt trib (int n, int back)
{
    if (n <= 1) return 1;
    if (C[n][back] != 0) return C[n][back];

    C[n][back] = 1;
    for (int i=1; i<=back; i++)
        C[n][back] += trib(n-i,back);
    return C[n][back];
}
int main()
{
    int n, back, Case=1;
    while (scanf("%d%d",&n,&back)){
        if (n > 60) break;
        printf("Case %d: %llu\n",Case++,trib(n,back));
    }
    return 0;
}