题解 1549: 蓝桥杯算法提高VIP-盾神与积木游戏 类似银行家算法

#include<iostream>
#include<algorithm>
#include<string>
using namespace std;
int m,n;
struct stu{
int have;
int need;
int lack;
};

bool cmp(stu a,stu b)
{
    return a.lack<b.lack;
}

int main()
{
   cin>>m;
   stu s[10005];
   while(m--)
   {
       cin>>n;
       for(int i=0;i<n;i++)
       {
           cin>>s[i].have>>s[i].need;
           s[i].lack=s[i].need-s[i].have;
       }
       sort(s,s+n,cmp);
       int sum=0;
       int flag=1;
       for(int i=0;i<n;i++)
       {
           if(s[i].lack<=0)//不缺
             sum+=s[i].have;
            else
            {
                if(sum+s[i].have>=s[i].need)//正好
                {
                    sum+=s[i].have;
                }
                else
                    flag=0;
            }

       }
       if(flag==0)
        cout<<"NO"<<endl;
       else
        cout<<"YES"<<endl;

   }
   return 0;
}

错误的：

#include<iostream>
#include<algorithm>
#include<string>
using namespace std;
int main()
{
    int m;
    cin>>m;
    int a[10005];
    int sum[10005];
    while(m--)
    {
        int n;
        cin>>n;
        int flag=0;
        int temp=0;
        for(int i=0;i<n;i++)
        {
            cin>>a[i];
            cin>>sum[i];
        }
        for(int i=0;i<n;i++)
        {
            if(a[i]==sum[i])
            {
                temp=a[i];
                flag++;
            }
            else if(a[i]<sum[i])
            {
                if(a[i]+temp>=sum[i])
                    flag++;
            }

        }
        if(flag==n)
            cout<<"YES"<<endl;
        else
            cout<<"NO"<<endl;

    }
    return 0;

}