UVA 洪水

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<string>
#include<algorithm>
#define maxn 30+5
using namespace std;
int main(){
    int m,n,total,sum,t,flag,num=0;
    int a[maxn][maxn],ss[maxn*maxn];
    double k,x,z;
    while(scanf("%d%d",&m,&n)==2){
    if(m==0&&n==0) break;
    num++;
    sum=0,t=0,flag=1;
    memset(a,0,sizeof(a));
    for(int i=0;i<m;i++){
        for(int j=0;j<n;j++){
            scanf("%d",&a[i][j]);
           sum+=a[i][j];
           ss[t++]=a[i][j];
        }
    }
    sort(ss,ss+t);
    scanf("%d",&total);
    z=n*m;  //z代表方格数
    k=total/100.00;
    while(flag==1){
    x=(k+sum)/z;
    if(x<ss[t-1]){
      sum-=ss[t-1];
        t--;
        z--;
    }else{
       flag=0;
    printf("Region %d\n",num);
    printf("Water level is %.2lf meters.\n",x);
    k=z/(n*m)*100;
    printf("%.2lf percent of the region is under water.\n",k);
    printf("\n");
     }
     }
    }
  return 0;
}