题目大意
给定一个环形路线,其上有n个加油站,每个加油站只能提供gas[i]单位的汽油,从i~i+1加油站要花费cost[i]单位汽油,返回能环绕一圈的起点位置
思路
暴力,赤裸裸的暴力,直接1Y了,此贴记录一下第一次白板1Y。以后水题就不开贴了。
代码
#include<iostream> #include<set> #include<vector> #include<map> using namespace std; int n = 0; int travel(int deep, int rest, int index, int cur,vector<int> &gas, vector<int> &cost) { if (deep == n)return index; if (rest+gas[cur]-cost[cur]<0 || travel(deep+1, rest+gas[cur]-cost[cur],index,(cur+1)%n, gas, cost) == -1) return -1; return index; } int canCompleteCircuit(vector<int> &gas, vector<int> &cost) { n = gas.size(); for (int i = 0; i < n; i ++){ int tmp = travel(0,0,i,i,gas,cost); if (tmp != -1)return tmp; } return -1; } int main() { int n; while (cin >> n){ vector <int> a,b; a.clear(); b.clear(); for (int i = 0; i < n; i ++){ int tmp1, tmp2; cin >> tmp1>>tmp2; a.push_back(tmp1); b.push_back(tmp2); } cout << "index:"<<canCompleteCircuit(a,b)<<endl; } return 0; }