View Code of Problem 133

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

int cmp(const void *a, const void *b){  
	return *(int*)a - *(int*)b;     //从小到大
}
 
int main(){
	int t,n,x,flag;
	int i,low,high;
	scanf("%d",&t);
	while(t--){
		scanf("%d %d",&n,&x);
		int s[n];
		for(i=0;i<n;i++){
			scanf("%d",&s[i]);
		}
		qsort(s,n,sizeof(s[0]),cmp);
		flag=0;
		for(low=0,high=n-1;low<high;){      //调节器
		    if(s[low]+s[high]==x){
		        flag=1;
		        break;
		    }else if(s[low]+s[high]<x){
		        low++;
		    }else{
		        high--;
		    }
		}
		if(flag==1){
		    printf("YES\n");
		}else{
		    printf("NO\n");
		}
	}
 
	return 0;
}