Function Run Fun hdu1579 递推

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http://acm.hdu.edu.cn/showproblem.php?pid=1579

此题首句：我们都爱递推，嗯哼？…………

简单递推。

#include <iostream>using namespace std;#define MAX 23#define N 21int w[MAX][MAX][MAX];void init(){int i,j,k;for (i=0;i<N;i++)for (j=0;j<N;j++)w[i][j][0]=1;for (j=0;j<N;j++)for (k=0;k<N;k++)w[0][j][k]=1;for (i=0;i<N;i++)for (k=0;k<N;k++)w[i][0][k]=1;for (i=1;i<N;i++)for (j=1;j<N;j++)for (k=1;k<N;k++)w[i][j][k]=w[i-1][j][k]+w[i-1][j-1][k]+w[i-1][j][k-1]-w[i-1][j-1][k-1];for (i=1;i<N;i++)for (j=i+1;j<N;j++)for (k=j+1;k<N;k++)w[i][j][k]=w[i][j][k-1]+w[i][j-1][k-1]-w[i][j-1][k];return ;}int main(){init();int a,b,c;while (scanf("%d%d%d",&a,&b,&c)!=EOF){if (a==-1&&b==-1&&c==-1)break;else if (a<=0||b<=0||c<=0)printf("w(%d, %d, %d) = 1\n",a,b,c);else if (a>20||b>20||c>20)printf("w(%d, %d, %d) = %d\n",a,b,c,w[20][20][20]);else printf("w(%d, %d, %d) = %d\n",a,b,c,w[a][b][c]);}return 0;}