I read 3 chars and run the follow DFA:
                one on in/out put
lost:
empty:
in/out:
input/output:
put:

here is my code:

#include <iostream>
#include <cstdio>
#include <cassert>
#include <cstdlib>
#include <string>

using namespace std;

inline bool good(char C)
{
    return (C >= 'a' && C <= 'z');
}

int a[5][4] = {{0, 0, 0, 0},
               {1, 0, 2, 4},
               {1, 0, 2, 3},
               {1, 1, 2, 4},
               {0, 1, 0, 0}};

char c[3];

bool get_ans()
{
    int n_u = 0, pos = 1;

    if (!good(c[2])) {
        return (c[0] == 'i' && c[1] == 'n');
    }

    bool n2 = 0;
    while (true)
    {
        if (pos == 0) return 0;
        if (n2) return (pos != 0 && pos != 4);

        c[0] = c[n_u % 3];

        for (int i = 3 - n_u; i < 3; i++)
        {
            c[i] = getc(stdin);
            if (!good(c[i])) {
                if (i == 0) return (pos != 0 && pos != 4);
                if (i == 1) return 0;
                n2 = 1;
                break;
            }
        }


        if (!n2 && c[0] == 'o' && c[1] == 'n' && c[2] == 'e') {
            pos = a[pos][0];
            n_u = 3;
            continue;
        }

        if (c[0] == 'o' && c[1] == 'n') {
            pos = a[pos][1];
            n_u = 2;
            continue;
        }

        if (!n2 && c[0] == 'o' && c[1] == 'u' && c[2] == 't') {
            pos = a[pos][2];
            n_u = 3;
            continue;
        }

        if (c[0] == 'i' && c[1] == 'n') {
            pos = a[pos][2];
            n_u = 2;
            continue;
        }

        if (!n2 && c[0] == 'p' && c[1] == 'u' && c[2] == 't') {
            pos = a[pos][3];
            n_u = 3;
            continue;
        }
        return 0;
    }
}

int main()
{
//    assert(freopen("inp.in", "r", stdin) != NULL);

    int n; assert(scanf("%d", &n) == 1);

    c[0] = getc(stdin);

    for (int i = 0; i < n; i++)
    {
        bool ok = 0;
        c[0] = getc(stdin);

        if (good(c[0])) {
            c[1] = getc(stdin);
            if (good(c[1])) {
                c[2] = getc(stdin);
                ok = get_ans();
            } else {
                ok = 0;
            }
        }

        if (ok) printf("YES\n");
        else printf("NO\n");
    }
}

Edited by author 10.12.2013 21:13

Edited by author 10.12.2013 21:15

Edited by author 10.12.2013 21:22