LETTers比赛第七场 奥数的烦恼

     状态为DP[x][y][z]=DP[x-1][y][z-1]+DP[x][y-1][z]+DP[x][y][z-1];注意一点数值为长整型！

#include<stdio.h>
#include<string.h>
const int maxn=20;
__int64 f[maxn][maxn][maxn];
int vis[maxn][maxn][maxn];
__int64 Solve(int a,int b,int c)
{
	if(a<0||b<0||c<0)return 0;
	if(vis[a][b][c])return f[a][b][c];
	vis[a][b][c]=1;
	__int64 &ans=f[a][b][c];
	ans=Solve(a-1,b,c)+Solve(a,b-1,c)+Solve(a,b,c-1);
	return ans;
}
int main()
{
//	freopen("testin","r",stdin);
//	freopen("testout1","w",stdout);
	int tt;
	scanf("%d",&tt);
	f[1][0][0]=1;
	f[0][1][0]=1;
	f[0][0][1]=1;
	//f[0][0][0]=0;
	while(tt--)
	{
		int a,b,c;
		scanf("%d%d%d",&a,&b,&c);
		memset(vis,0,sizeof(vis));
		vis[1][0][0]=1;vis[0][1][0]=1;vis[0][0][1]=1;
		vis[0][0][0]=1;
		printf("%I64d\n",Solve(a,b,c));
	}
	return 0;
}