第374题---Guess Number Higher or Lower

• 题意描述

  • 猜数游戏

• 思路

  • 二分查找

• 代码

  // 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 {
  public:
      int guessNumber(int n) {
          int start = 1;
          int end = n;
          
          while (start <= end) {
              int mid = start + (end - start) / 2;
              int g = guess(mid);
              if(g == 0)
                  return mid;
              else if(g == 1)
                  start = mid+1;
              else 
                  end = mid-1;
          }
          return -1;
      }
  };