Problem
We are playing the Guess Game. The game is as follows:
I pick a number from 1 to n. You have to guess which number I picked.
Every time you guess wrong, I'll tell you whether the number is higher or lower.
You call a pre-defined API guess(int num) which returns 3 possible results (-1, 1, or 0):
-1 : My number is lower
1 : My number is higher
0 : Congrats! You got it!
Example
Input: n = 10, pick = 6
Output: 6
Code
// 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
static int var = [](){
std::ios::sync_with_stdio(false);
cin.tie(NULL);
return 0;
}();
int guess(int num);
class Solution {
public:
int guessNumber(int n) {
long left = 1;
long right = n;
long mid;
while(1){
mid = (left+right)/2;
cout << mid << endl;
switch(guess(mid)){
case -1:
right = mid-1;
break;
case 1:
left = mid+1;
break;
case 0:
return mid;
}
}
}
};
Result
374. Guess Number Higher or Lower.png
