guess-number-higher-or-lower

// Forward declaration of guess API.
// @param num, your guess
// @return -1 if my number is lower, 1 if my number is higher, otherwise return 0
int guess(int num);

class Solution {
long long lb;
long long hb;
public:
int guessNumber(int n) {
lb = 1;
hb = n;
if (lb >= hb) {
return lb;
}
int g = (lb + hb) / 2;
int r = guess(g);
while (r != 0) {
if (r < 0) {
hb = g - 1;
}
else {
lb = g + 1;
}
if (lb >= hb) {
return lb;
}
g = (lb + hb) / 2;
r = guess(g);
}
return g;
}
};