正方形;

来源：互联网发布：matlab 稀疏矩阵求逆编辑：程序博客网时间：2024/04/25 10:22

import java.util.Scanner;
public class SqureForm {
public static int[] data;
public static String[] res=new String[100];
public static int respc=0;

public static int[] visit;
public static int bianchang;
public static int flag;
public static int geshu;
/*public static boolean isFind(int b[],int bianchang,int geshu){
  int biansum=0;
  int biancount=0;
  for(int i=0;i<geshu;i++){
   biansum+=b[i];
   if(biansum==bianchang) {
    biansum=0;
    biancount++;
   }
   if(biancount==3) return true;;
  }

  return false;
}*/
public static void dFS(int tempsum,int sange,int step){
  if(flag==1) return;
  if(tempsum==bianchang) {
   dFS(0,sange+1,0);
   if(flag==1) return;
  }

  if(sange==3){
    flag=1;
    res[respc++]="yes";
    return;
  }

  for(int i=step;i<geshu;i++){
   int tempand=tempsum+data[i];
   if(visit[i]==0&&tempand<=bianchang){
    visit[i]=1;
    dFS(tempand,sange,step+1);
    visit[i]=0;
   }
  }
}
    public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    int testnum=sc.nextInt();
    int iunum=testnum;
    while(testnum-->0){
      flag=0;

      geshu=sc.nextInt();
      data=new int[geshu];

      visit=new int[geshu];
      int sum=0;
      int max=0;
      for(int i=0;i<geshu;i++){
       data[i]=sc.nextInt();
       sum+=data[i];
       if(max<data[i]) max=data[i];
      }
      if(sum%4!=0){
       res[respc++]="no";
       continue;
      }
      bianchang=sum/4;
      if(max>bianchang) {
       res[respc++]="no";
       continue;
      }

      for(int i=0;i<geshu-1;i++){
       int maxi=data[i];
       int maxindex=i;
       for(int j=i+1;j<geshu;j++){
        if(maxi<data[j]){
         maxi=data[j];
         maxindex=j;
        }
       }
       data[maxindex]=data[i];
       data[i]=maxi;
      }


      dFS(0,0,0);
      if(flag==0) res[respc++]="no";
      }
      for(int i=0;i<iunum;i++){
    System.out.println(res[i]);
      }

   }
}

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