NO7——二分
1 int binsearch(int *t,int k,int n) 2 {//t为数组,k是要查找的数,n为长度,此为升序 3 int low = 1,high = n,mid; 4 while(low<=high) 5 { 6 mid = (low+high)/2; 7 if(k == t[mid]) 8 return mid; 9 else if(k<t[mid]) 10 high = mid-1; 11 else 12 low = mid+1; 13 } 14 return -1; 15 }