134. Gas Station

Problem:

思路：

Solution (C++):

int canCompleteCircuit(vector<int>& gas, vector<int>& cost) {
    int n = gas.size(), tank(0), start(0), lack(0);
    
    for (int i = 0; i < n; ++i) {
        tank += (gas[i] - cost[i]);
        if (tank < 0) {
            start = i+1;
            lack += tank;
            tank = 0;
        }
    }
    
    return (lack + tank < 0) ? -1: start;
}

性能：

Runtime: 8 ms  Memory Usage: 9.1 MB