134. Gas Station 不会做. 1. 朴素的想法,就是针对每个位置判断一下,然后返回合法的位置,复杂度O(n^2),显然会超时. 把这道题转化一下吧,求哪些加油站不能走完一圈回到自己,要求O(N)的复杂度. 如果sgas < scost,那么显然所有的站点都无法走完一圈. 2. 考虑怎么进行化简,寻找有没有什么可以利用的性质,考虑可不可以进行递推,对每个位置求出gas - cost,然后很明显观察到如果一个位置为负数,那么这个位置显然不能走完一圈,那么接下来 考虑怎么进行简化,找到负…

There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with an e…

There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with an e…

题目: There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with…

贪心:尽量将gas[i]-cost[i]>0的放在前面,gas[i]-cost[i]<0的放在后面.(路程的前面有汽油剩下,耗汽油的放在路程的后面). 能否全程通过的 条件 是:sum(gas[i])>=sum(cost[i]),不满足这个条件就不能全程走一遍: 起点 i 满足的 必要 条件 是:额外剩下的gas(additional_gas)要大于等于0,即 gas[i]-cost[i]>=0: 另外需满足: 找出某站点 i_save ,经过这个站点剩下的gas最多,找出某站点…

因为gas的总数大于cost总时间.你将能够圈住整个城市. 第一溶液: 如果一開始有足够的油.从位置i出发.到位置k时剩余的油量为L(i,k). 对随意的k.L(i,k)依据i的不同,仅仅相差常数. 我们仅仅须要找到最小的L(0, k)相应的k,k+1为所求. 代码例如以下: int canCompleteCircuit(vector<int> &gas, vector<int> &cost) { int start = 0; int curGas = 0, min…

There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with an e…

Recording my thought on the go might be fun when I check back later, so this kinda blog has no intention to be read by others(its just for recording, not article). but if you insist, hope you enjoy it. if you find me wrong, please let me know, very a…

https://leetcode.com/problems/gas-station/ 题目: There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next…

There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with an e…