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…

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…

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…

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…

Gas Station 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 journ…

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…