HDU 1902 the dragon of loowater

The first question in the White Book is greedy.

After sorting, scan it again.

#include<cstdio>#include<cstring>#include<string>#include<queue>#include<algorithm>#include<map>#include<stack>#include<iostream>#include<list>#include<set>#include<cmath>#define INF 0x7fffffff#define eps 1e-8#define LL long long#define PI 3.141592654#define CLR(a,b) memset(a,b,sizeof(a))#define FORi(n) for(int i=0;i<n;i++)#define FORj(n) for(int j=0;j<n;j++)#define FORk(n) for(int k=0;k<n;k++)#define debug puts("==fuck==")#define acfun std::ios::sync_with_stdio(false)#define SIZE 1000+10using namespace std;bool cmpa(int a,int b){    return a<b;}int v[20001];int main(){    int a[20001],b[20001],i,j,n,m;    while(scanf("%d%d",&n,&m),n||m)    {        FORi(n)        scanf("%d",&a[i]);        FORi(m)        scanf("%d",&b[i]);        sort(a,a+n,cmpa);        sort(b,b+m,cmpa);        int sum=0;        CLR(v,0);        bool ok=0;        for(i=n-1;i>=0;i--)        {            ok=0;            FORj(m)            if(!v[j]&&b[j]>=a[i])            {                v[j]=1,sum+=b[j];                ok=1;break;            }            if(!ok)break;        }        if(!ok)puts("Loowater is doomed!");        else printf("%d\n",sum);    }}

HDU 1902 the dragon of loowater