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poj-1384 Piggy-Bank

 

poj-1384 Piggy-Bank 地址:http://poj.org/problem?id=1384

 

题意:

知道盒子里面的物体的总重量,得到每一种硬币的价格和重量,求最少钱构成盒子物体总重量的钱的数量。 

 

分析:

典型的不限重背包问题。当然维度也是在可以接受的范围, 直接设置dp数组进行min操作。

 

 

 

#include <iostream> #include <cstdio> #include <cstdlib> #include <cstring> #include <string> using namespace std; const int maxn = 505; const int max_val = 10000; int E,F, n, dp[max_val+5]; struct Node{    int p,w; }nd[maxn]; int cmp(const void* a, const void* b){    Node* aa = (Node *)a;     Node* bb = (Node *)b;     return (bb->w*1.0)/(bb->p*1.0) - (aa->w*1.0)/(aa->p*1.0);  }int main(){    freopen("in.txt", "r", stdin);     int test_num, i, j;     scanf("%d", &test_num);     while(test_num--){        scanf("%d %d", &E, &F);         scanf("%d", &n);         for(i=0; i<n; i++){            scanf("%d %d", &nd[i].p, &nd[i].w);         }        memset(dp, 0x3f3f3f3f, sizeof(dp));          dp[0] = 0;         for(i=0; i<n; i++){            for(j=nd[i].w; j<=(F-E); j++){                if(dp[j - nd[i].w] != 0x3f3f3f3f ){                    dp[j] = min(dp[j-nd[i].w]+nd[i].p, dp[j]);                 }            }        }        if(dp[F-E] == 0x3f3f3f3f){            printf("This is impossible.\n");        }else{            printf("The minimum amount of money in the piggy-bank is %d.\n", dp[F-E]);        }    }    return 0; }

 

poj-1384 Piggy-Bank