PAT-1065.單身狗-19分-102ms

#include <stdio.h>
#define MAX 50001
int main(){
   int n;scanf("%d",&n);
  int couple[MAX];
  for (int i=0;i<n;i++){
    int cc;
    int cct;
    scanf("%d %d",&cc,&cct);
    //夫妻互存 
    couple[cc]=cct;
    couple[cct]=cc;  
  }
  int m;scanf("%d",&m);
  int people[MAX];
  for (int i=0;i<m;i++){
    int cc;
    scanf("%d",&cc);
    people[i]=cc;
  }
  int coupletrue[MAX];//有配偶的人
  int coupletruetotal=0; 
  int dog[MAX];
  int total=0;
  for (int i=0;i<m;i++){//客人  判斷是否有配偶 
    if (couple[people[i]]==0) {//如果 沒有 存起來 (鐵單身) 
      dog[total]=people[i];
      total++; 
    }else {//如果 有 先存起來 進行下一步判斷 (銀水) 
      coupletrue[coupletruetotal]=people[i];
      coupletruetotal++;
    }
  }
  for (int i=0;i<coupletruetotal;i++){// 通過剩下的值互相匹配 
    int j=0;
    for (j=0;j<coupletruetotal;j++){
      if (couple[coupletrue[i]]==coupletrue[j]){
        break;  
      } 
    } 
    if (j==coupletruetotal){
      dog[total]=coupletrue[i];
      total++;
    }
  } 
  printf ("%d\n",total);
  for (int i=0;i<total-1;i++){
    for (int j=i+1;j<total;j++){
      if (dog[i]>dog[j]){
        int temp=dog[i];
        dog[i]=dog[j];
        dog[j]=temp;
      }
    }
  }
  for (int i=0;i<total;i++){
    printf("%d",dog[i]);
    if (i<total-1) printf(" "); 
  }
  return 0;
}