134. Gas Station

目录

题目描述

暴力法

贪心法

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题目描述

134. Gas Station

暴力法

会超时。

class Solution {
public:int canCompleteCircuit(vector<int>& gas, vector<int>& cost) {int len = gas.size();int tank = 0;for(int start = 0; start < len;start++){tank = gas[start];int cur = start;while(tank >= cost[cur]){tank -= cost[cur];cur++;cur =  cur%len;if(cur == start)return start;tank += gas[cur];}}return -1;}
};

贪心法

class Solution {
public:int canCompleteCircuit(vector<int>& gas, vector<int>& cost) {int len = gas.size();int start = 0;int cursum = 0;int totalsum = 0;for(int i = 0;i < len;i++){cursum += (gas[i] - cost[i]);totalsum += (gas[i] - cost[i]);if(cursum < 0){start = i+1;cursum = 0;}}if(totalsum < 0)return -1;return start;}
};