#include<stdio.h> # define k 3 int main() { int r[10]={0,2,4,5,7,9,12,16,19,20}; /*0,1,2,3,4,5,6,,7,,8,,9*/ int low,mid,high; low=0; high=9; while (low<=high) { mid=(low+high)/2; if(k==r[mid]) { printf("%d",mid); return 0; } else if(k<r[mid]) high=mid-1; else low=mid+1; } printf("Don't find item\n"); return 0; }