K SUM My Submissions http://www.lintcode.com/en/problem/k-sum/ 题目来自九章算法 13% Accepted Given n distinct positive integers, integer k (k <= n) and a number target. Find k numbers where sum is target. Calculate how many solutions there are? Example Given…

4 Pointer solution. Key: when moving pointers, we skip duplicated ones. Ref: https://github.com/xbz/lintcode/blob/master/4_sum/4sum.cpp class Solution { void nextUnique(vector<int> &num, size_t &j) { ]) ++j; } public: vector<vector<int…

Subarray Sum 原题链接:http://lintcode.com/zh-cn/problem/subarray-sum/# Given an integer array, find a subarray where the sum of numbers is zero. Your code should return the index of the first number and the index of the last number. 样例 Given [-3, 1, 2, -…

For this problem we need to learn a new trick that if your start sum up all elements in an array. When you start from a to b to sum up all elements, if the result is zero, and also the summation of all elements from index a to c ( c<=b ) is zero. The…

Given an array of integers, find two numbers such that they add up to a specific target number. The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. Please note that…

Given an integer matrix, find a submatrix where the sum of numbers is zero. Your code should return the coordinate of the left-up and right-down number. Have you met this question in a real interview? Yes Example Given matrix [ [1 ,5 ,7], [3 ,7 ,-8],…

Given an integer array in the construct method, implement two methods query(start, end) and modify(index, value): For query(start, end), return the sum from index start to index end in the given array. For modify(index, value), modify the number in t…

Given an integer array (index from 0 to n-1, where n is the size of this array), and an query list. Each query has two integers [start, end]. For each query, calculate the sum number between index start and end in the given array, return the result l…

Given an integer array, find a subarray with sum closest to zero. Return the indexes of the first number and last number. Have you met this question in a real interview? Yes Example Given [-3, 1, 1, -3, 5], return [0, 2], [1, 3], [1, 1], [2, 2] or [0…

Naive solution is O(n^4). But on 1 certain dimension, naive O(n^2) can be O(n) by this well-known equation: sum[i..j] = sum[0..j] - sum[0..i]. And pls take care of several corner cases. class Solution { public: /** * @param matrix an integer matrix *…