题解 | #称砝码#

#include <stdio.h>
#include <string.h>

int main(){
    int n;
    while(~scanf("%d",&n)){
        int wei[n];
        int num[n];                                     
        int i =0;
        for(i=0;i<n;i++)
         scanf("%d",&wei[i]);

        int numall = 0;
        int total = 0;
        for(i=0;i<n;i++)
        { 
            scanf("%d",&num[i]);
            numall+=num[i];
            total+= wei[i]*num[i];
        }

        int arr[numall];
        memset(arr, 0, sizeof(arr));
        int k=0;
        for(i=0;i<n;i++)
        {   
            int tem = wei[i];
            for(int j=0;j<num[i];j++)
            {
                arr[k++] = tem;
            }
        }

        int wei_exist[total+1];
        memset(wei_exist, 0, sizeof(wei_exist));
        wei_exist[0]=1;

        for(i=0;i<numall;i++)
        {
            for(int k = total;k>=0;k--)
            {
                if(wei_exist[k] == 1)
                {
                    wei_exist[k+arr[i]] =1;
                }
            }
        }

        int count =0;
        for(i=0;i<=total;i++)
        {
            count +=wei_exist[i];
        }
        printf("%d",count);





    }
}