hdu3576 Elevators in Jiayuan Students' Apartment

这是一道DP问题，觉得挺有意思的，所以时隔数日又写了一遍……

#include<iostream>#include<cstdio>using namespace std;int dp[20][20][20][20];int a[20];int main(){    int f,i,j,k;    int t, cases;    scanf("%d", &cases);    t = 1;    while(t <= cases)    {            int c,m;            scanf("%d %d", &c, &m);                        memset(a, 0, sizeof(a));            int tmp;            for(i=0; i<m; i++)            {                     scanf("%d", &tmp);                     a[tmp] ++;                     }                        memset(dp, -1, sizeof(dp));            dp[1][0][0][0] = 0;            for(f=2; f<=16; f++)            for(i=0; i<=c; i++)            for(j=0; j<=c; j++)            for(k=0; k<=c; k++)            {                     if(dp[f-1][i][j][k] == -1) continue;                                          int x,y,z;                     for(x=0; x<=a[f]; x++)                     for(y=0; y<=a[f]; y++)                     {                              z = a[f] - x - y;                                                            if(x + y > a[f]) continue;                              if(x+i > c|| y+j>c || z+k > c) continue;                                                            tmp = dp[f-1][i][j][k] + (x!=0)+(y!=0)+(z!=0);                              if(dp[f][x+i][y+j][z+k] == -1 || dp[f][x+i][y+j][z+k] > tmp)                              dp[f][x+i][y+j][z+k] = tmp;                              }                     }            int res = 10000000;            for(i=0; i<=c; i++)            for(j=0; j<=c; j++)            {                     if(i+j>m) continue;                     if(dp[16][i][j][m-i-j] == -1) continue;                     if(dp[16][i][j][m-i-j] < res)                      res = dp[16][i][j][m-i-j];              }              printf("Case %d: %d\n", t, res);              t ++;            }    return 0;    }