标签：有一个 esc number color turn bottom ret 解法 code
class Solution { public: int MoreThanHalfNum_Solution(vector<int> numbers) { int len = numbers.size(); map<int, int> m; int count; for (int i = 0; i < len; i++) { count = ++m[numbers[i]]; if (count > len / 2) return numbers[i]; } return 0; } };
解法二：
排序以后，若存在超过一半的数字，该数字必在中间，于是再遍历一遍确认该数字是否超过一半。
class Solution { public: int MoreThanHalfNum_Solution(vector<int> numbers) { sort(numbers.begin(), numbers.end()); int len = numbers.size(); int a = numbers[len / 2]; int count = 0; for (int i = 0; i < len; i++) { if (numbers[i] == a) count++; } return count > (len / 2) ? a : 0; } };
解法三：
利用数组特性，从前往后遍历，每两个比较，若不同则删去这两个数字，若存在超过一半的数字，最后剩下的一定是该数字。
class Solution { public: int MoreThanHalfNum_Solution(vector<int> numbers) { int len = numbers.size(); if (len == 0) return 0; int count = 1; int res = numbers[0]; for (int i = 1; i < len; i++) { if (res == numbers[i]) count++; else count--; if (count == 0) { res = numbers[i]; count++; } } count = 0; for (int i = 0; i < len; i++) { if (numbers[i] == res) count++; if (count > len / 2) return res; } return 0; } };
标签：有一个 esc number color turn bottom ret 解法 code
原文地址：https://www.cnblogs.com/ruoh3kou/p/10098683.html
