[69] Sqrt(x)

懶得思考QQ

照抄了一題 QQ

int mySqrt(int x) {

if (x<2)

return x;

int left=1;

int right= x;

while (left < right)

{

int mid = left + (right-left)/2;

int check = x/mid;

if (check == mid)

return mid;

else if (check < mid)

right = mid;

else

left = mid +1;

}

return right-1;

}