374. Guess number Higher or Lower

Topic:

We are playing the Guess Game. The game is as follows:

I pick a number from 1 to N. You had 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:

n = ten, I pick 6.Return 6.            

Answer:
Two-point search ideas

1 //Forward Declaration of the Guess API.2 //@param num, your guess3 //@return-1 If my number is lower, 1 if my number is higher, otherwise return 04 intGuessintnum);5 6 classSolution {7  Public:8     intGuessnumber (intN) {9         intlow=1, high=N;Ten         intmid; One          while(low<=High ) { Amid=low+ (high-low)/2;//Direct Write mid= (Low+high)/2 overflow -             if(Guess (mid) = =0){ -                 returnmid; the             } -             Else if(Guess (mid) ==-1){ -high=mid-1; -             } +             Else{ -Low=mid+1; +             } A         } at         returnmid; -     } -};

374. Guess number Higher or Lower