二分查找

int binary_search(int array[], int n, intvalue)

{

int left=0,right=n-1;

while(left<=right)//防溢出，移位-高效。

{

int middle = left+ ((right-left)>>1);

if(array[middle]>value) right = middle - 1;

else if(array[middle] < value ) left = middle + 1；

else returnmiddle;

}

return -1;

}