Title : Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution. For example, given array S…

Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution. For example, given array S = {-1 2…

思路 排序 枚举一个数a 双指针移动法确定b和c 求和,更新最接近的值 复杂度 T(n)=O(n2)  M(n)=O(1)T(n)=O(n^2) \; M(n)=O(1)T(n)=O(n2)M(n)=O(1) class Solution { public int threeSumClosest(int[] nums,int target) { int sum = nums[0]+nums[1]+nums[2]; int ans = sum; int minDiff = Ma…

思路一为遍历: public int thirdSolution(int[] nums, int target) { int result = nums[0] + nums[1] + nums[2]; Arrays.sort(nums); for (int i = 0; i < nums.length - 2; i++) { int start = i + 1, end = nums.length - 1; while (start < end) { int tmp = nums[i] + n…

Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution. For example, given array S = {-1 2…

利用堆栈:http://oj.leetcode.com/problems/evaluate-reverse-polish-notation/http://oj.leetcode.com/problems/longest-valid-parentheses/ (也可以用一维数组,贪心)http://oj.leetcode.com/problems/valid-parentheses/http://oj.leetcode.com/problems/largest-rectangle-in-histo…

463. Island Perimeterhttps://leetcode.com/problems/island-perimeter/就是逐一遍历所有的cell,用分离的cell总的的边数减去重叠的边的数目即可.在查找重叠的边的数目的时候有一点小技巧,就是沿着其中两个方向就好,这种题目都有类似的规律,就是可以沿着上三角或者下三角形的方向来做.一刷一次ac,但是还没开始注意codestyle的问题,需要再刷一遍. class Solution { public: int islandPerime…

利用堆栈:http://oj.leetcode.com/problems/evaluate-reverse-polish-notation/http://oj.leetcode.com/problems/longest-valid-parentheses/ (也可以用一维数组,贪心)http://oj.leetcode.com/problems/valid-parentheses/http://oj.leetcode.com/problems/largest-rectangle-in-histo…

原链接:http://blog.csdn.net/yangliuy/article/details/44514495 注:此分类仅供大概参考,没有精雕细琢.有不同意见欢迎评论~ 利用堆栈:http://oj.leetcode.com/problems/evaluate-reverse-polish-notation/http://oj.leetcode.com/problems/longest-valid-parentheses/ (也可以用一维数组,贪心)http://oj.leetcode.…

https://leetcode.com/problems/3sum-closest/ [描述] Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly…