#define M 10 #include stdio.h int main(){ int n,low,mid,high,flag; int a = {2,5,9,11,15,21,30,42,55,69}; low = 0; high = M - 1; flag = 0; printf("Input a number:\n"); scanf("%d",n); while(low = high){ mid = (low + high) / 2; if(n == a ){ flag = 1; break; }else if(n ...