动态规划入门——Dividing

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分析：一个多重背包问题、由于value比较特殊、用贪心也水过了、但是没有办法证明贪心的正确性、但又找不出反例、所以两种方法都做一下、

#include<stdio.h>int w[7];int packback(int s,int num){    if(num<=0)return 0;    if(s==0)return 1;    while(w[num]==0||s<num)        num--;    w[num]--;    return (packback(s-num,num)||packback(s,num-1));}int main(){    int cas=1;    while(scanf("%d",&w[1])!=EOF){        int sum=w[1];        for(int i=2;i<=6;i++){            scanf("%d",&w[i]);            sum+=(w[i]*i);        }        if(sum==0)break;        printf("Collection #%d:\n",cas);cas++;        int flag=0;        if(sum%2!=0){            flag=0;        }        else{            sum/=2;            flag=packback(sum,6);        }        if(flag==0)            printf("Can't be divided.\n");        else            printf("Can be divided.\n");        printf("\n");    }    return 0;}