#include <stdio.h>
#include<stdlib.h>
 
int binary_search(int a[],int n,int x){
  int i,ret=-1;
  for(i=0;i<n;i++){
    if(a[i]==x){
    ret=i;
    break;
    }
  }
  return ret;
}//探したい数xのインデックス(何番目か)を返す関数
 
int main(void) {
int n,x,i;//配列のサイズn,探したい数x
int *a;
int ans=-1;
  scanf("%d %d",&n,&x);
  a=(int*)malloc(sizeof(int)*n);
  if(a==NULL){printf("ERROR\n");return -1;}//エラー処理
  for(i=0;i<n;i++){scanf("%d",&a[i]);}//配列aの値代入
  ans=binary_search(a,n,x);
  if(ans!=-1)printf("a[%d]=%d\n",ans,a[ans]);//-1以外が返されたら答えとして表示
  else printf("not found\n");//-1が返されたらnot foundと表示
  free(a);//領域解放
  return 0;
}

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