hdu 1022 Train Problem I（栈）

标记现在已经匹配到o1的第几列车了，o2从头开始，如果不匹配把o1就放入栈中，匹配后出栈并比较栈顶与o1的下一辆，匹配继续出，不匹配就继续进栈

 

#include <iostream>
#include <string>
#include <cstdio>
#include <stack>
using namespace std;
int main()
{
    int n;
    while (scanf("%d", &n) != EOF)
    {
        string o1, o2;
        cin >> o1 >> o2;
        stack<int> s;
        bool flag[1000] = {0};
        int i = 0, j = 0, k = 1;    //i,j,k分别为O1,O2,result下标
        s.push(o1[0]);
        flag[0] = 1;
        while (i < n && j < n)
        {
            if (!s.empty() && s.top() == o2[j])
            {
                s.pop();
                flag[k++] = 0;
                ++j;
            }
            else
            {
                s.push(o1[++i]);
                flag[k++] = 1;
            }
        }
        if (i == n)
            cout << "No." << endl;
        else
        {
            cout << "Yes." << endl;
            for (int i = 0; i < k; ++i)
                if (flag[i])
                    cout << "in" << endl;
                else
                    cout << "out" << endl;
        }
        cout << "FINISH" << endl;
    }
    system("pause");
    return 0;
}