1 /*************************************************************************
 2 > File Name: GasStation.cpp
 3 > Author: zhoukang1991
 4 > Mail: zhoukang199191@126.com
 5 > Created Time: 2014年08月14日 星期四 02时32分44秒
 6 ************************************************************************/
 7 #include <iostream>
 8 #include <vector>
 9 using namespace std;
10 //算法：当出现了sum小于零之后，直接从后面开始判断
11 class Solution{
12 public:
13 int canCompleteCircuit(vector<int> &gas, vector<int> &cost){
14 int sum = 0;
15 int total = 0;
16 int i;
17 vector<int> diff;
18 for(i = 0 ; i < gas.size() ; ++i){
19 diff.push_back(gas[i]-cost[i]);
20 }
21 int j = -1;
22 for(i = 0 ; i < diff.size() ; ++i){
23 sum += diff[i];
24 total += diff[i];
25 if(sum < 0){
26 j = i;sum = 0;
27 }
28 }
29 if(total < 0)return -1;
30 else return j+1;
31 }
32 };
33 int main(){
34 return 0;
35 }