답안 #26175 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
26175	2017-06-28T08:21:46 Z	chpipis	세 명의 친구들 (BOI14_friends)	C++11	100 / 100	116 ms	19600 KB

friends

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define pf push_front
#define iter(v, i) for (__typeof__((v).begin()) i = (v).begin(); i != (v).end(); i++)
#define fast_io_without_cstdio ios_base::sync_with_stdio(false), cin.tie(NULL)
#define all(v) (v).begin(), (v).end()
#define rep(i, s, e) for (int i = s; i < e; i++)

#ifdef __linux__
#define gc getchar_unlocked
#define pc putchar_unlocked
#else
#define gc getchar
#define pc putchar
#endif

#if __cplusplus <= 199711L
template<class BidirIt>
BidirIt prev(BidirIt it, typename iterator_traits<BidirIt>::difference_type n = 1) {
    advance(it, -n);
    return it;
}

template<class ForwardIt>
ForwardIt next(ForwardIt it, typename iterator_traits<ForwardIt>::difference_type n = 1) {
    advance(it, n);
    return it;
}
#endif

typedef long long ll;
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef long double ldouble;

const double EPS = 1e-9;
const double PI = 3.141592653589793238462;

template<typename T>
inline T sq(T a) { return a * a; }

//#ifdef LOCAL_MACHINE
//#endif

const int MAXN = 2e6 + 5;
const int BASE = 29;
const int MOD = 1e9 + 7;

inline int mul_mod(int a, int b) {
    return a * 1LL * b % MOD;
}

inline void add_mod(int &a, int b) {
    a += b;
    if (a >= MOD) a -= MOD;
}

inline void sub_mod(int &a, int b) {
    a -= b;
    if (a < 0) a += MOD;
}

char str[MAXN];
int h[MAXN], bpow[MAXN];

int get_hash(int i, int j) {
    if (i > j) return 0;
    int ret = h[j];
    sub_mod(ret, mul_mod(h[i - 1], bpow[j - i + 1]));
    return ret;
}

int main() {
    bpow[0] = 1;
    for (int i = 1; i < MAXN; i++)
        bpow[i] = mul_mod(bpow[i - 1], BASE);
    //freopen("", "r", stdin);
    //freopen("", "w", stdout);
    int n;
    scanf("%d", &n);
    scanf("%s", str + 1);
    if (!(n & 1)) {
        puts("NOT POSSIBLE");
        return 0;
    }
    for (int i = 1; i <= n; i++) {
        h[i] = mul_mod(h[i - 1], BASE);
        add_mod(h[i], str[i] - 'A' + 1);
    }
    set<int> sol;
    int ans = -1, cnt = 0;
    for (int i = 1; i <= n; i++) {
        int left, right;
        if (i <= (n / 2) + 1) {
            left = get_hash(1, i - 1);

            int len = (i - 1);
            int rem = (n / 2) - len;

            left = mul_mod(left, bpow[rem]);
            add_mod(left, get_hash(i + 1, i + 1 + rem - 1));

            assert(i + 1 + rem - 1 == n - (n / 2));

            right = get_hash(n - (n / 2) + 1, n);
        } else {
            left = get_hash(1, n / 2);

            int len = n - (i + 1) + 1;
            int rem = (n / 2) - len;

            right = get_hash((n / 2) + 1, (n / 2) + 1 + rem - 1);
            right = mul_mod(right, bpow[len]);
            add_mod(right, get_hash(i + 1, n));
        }
        if (left == right) {
            sol.insert(left);
            //cnt++;
            ans = i;
            //printf("I can replace char at pos %d\n", i);
        }
    }
    cnt = (int)sol.size();
    if (cnt > 1)
        puts("NOT UNIQUE");
    else if (cnt == 0)
        puts("NOT POSSIBLE");
    else {
        for (int i = 1, c = 0; c < (n / 2); i++) {
            if (ans == i) continue;
            c++;
            pc(str[i]);
        }
        pc('\n');
    }
    return 0;
}

Compilation message

friends.cpp: In function 'int main()':
friends.cpp:87:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
                    ^
friends.cpp:88:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s", str + 1);
                         ^

Subtask #1
35.0 / 35.0

#	결과	실행 시간	메모리	Grader output
1	Correct	16 ms	19600 KB	Output is correct
2	Correct	16 ms	19600 KB	Output is correct
3	Correct	13 ms	19600 KB	Output is correct
4	Correct	13 ms	19600 KB	Output is correct
5	Correct	16 ms	19600 KB	Output is correct
6	Correct	16 ms	19600 KB	Output is correct
7	Correct	9 ms	19600 KB	Output is correct
8	Correct	13 ms	19600 KB	Output is correct
9	Correct	16 ms	19600 KB	Output is correct
10	Correct	9 ms	19600 KB	Output is correct
11	Correct	16 ms	19600 KB	Output is correct
12	Correct	16 ms	19600 KB	Output is correct
13	Correct	16 ms	19600 KB	Output is correct
14	Correct	13 ms	19600 KB	Output is correct
15	Correct	13 ms	19600 KB	Output is correct
16	Correct	13 ms	19600 KB	Output is correct
17	Correct	9 ms	19600 KB	Output is correct
18	Correct	13 ms	19600 KB	Output is correct
19	Correct	6 ms	19600 KB	Output is correct
20	Correct	16 ms	19600 KB	Output is correct
21	Correct	16 ms	19600 KB	Output is correct
22	Correct	16 ms	19600 KB	Output is correct
23	Correct	13 ms	19600 KB	Output is correct
24	Correct	13 ms	19600 KB	Output is correct
25	Correct	13 ms	19600 KB	Output is correct
26	Correct	16 ms	19600 KB	Output is correct
27	Correct	16 ms	19600 KB	Output is correct
28	Correct	13 ms	19600 KB	Output is correct
29	Correct	13 ms	19600 KB	Output is correct
30	Correct	19 ms	19600 KB	Output is correct
31	Correct	13 ms	19600 KB	Output is correct
32	Correct	13 ms	19600 KB	Output is correct
33	Correct	16 ms	19600 KB	Output is correct
34	Correct	16 ms	19600 KB	Output is correct
35	Correct	16 ms	19600 KB	Output is correct
36	Correct	13 ms	19600 KB	Output is correct
37	Correct	13 ms	19600 KB	Output is correct
38	Correct	16 ms	19600 KB	Output is correct
39	Correct	9 ms	19600 KB	Output is correct
40	Correct	6 ms	19600 KB	Output is correct
41	Correct	13 ms	19600 KB	Output is correct
42	Correct	13 ms	19600 KB	Output is correct
43	Correct	19 ms	19600 KB	Output is correct
44	Correct	19 ms	19600 KB	Output is correct
45	Correct	16 ms	19600 KB	Output is correct
46	Correct	9 ms	19600 KB	Output is correct
47	Correct	16 ms	19600 KB	Output is correct
48	Correct	9 ms	19600 KB	Output is correct
49	Correct	13 ms	19600 KB	Output is correct
50	Correct	16 ms	19600 KB	Output is correct
51	Correct	13 ms	19600 KB	Output is correct
52	Correct	19 ms	19600 KB	Output is correct
53	Correct	9 ms	19600 KB	Output is correct
54	Correct	9 ms	19600 KB	Output is correct

Subtask #2
65.0 / 65.0

#	결과	실행 시간	메모리	Grader output
1	Correct	96 ms	19600 KB	Output is correct
2	Correct	109 ms	19600 KB	Output is correct
3	Correct	116 ms	19600 KB	Output is correct
4	Correct	116 ms	19600 KB	Output is correct
5	Correct	103 ms	19600 KB	Output is correct
6	Correct	26 ms	19600 KB	Output is correct
7	Correct	106 ms	19600 KB	Output is correct
8	Correct	109 ms	19600 KB	Output is correct
9	Correct	99 ms	19600 KB	Output is correct
10	Correct	103 ms	19600 KB	Output is correct
11	Correct	83 ms	19600 KB	Output is correct
12	Correct	9 ms	19600 KB	Output is correct
13	Correct	13 ms	19600 KB	Output is correct
14	Correct	16 ms	19600 KB	Output is correct
15	Correct	13 ms	19600 KB	Output is correct
16	Correct	9 ms	19600 KB	Output is correct
17	Correct	16 ms	19600 KB	Output is correct
18	Correct	16 ms	19600 KB	Output is correct
19	Correct	9 ms	19600 KB	Output is correct
20	Correct	13 ms	19600 KB	Output is correct
21	Correct	16 ms	19600 KB	Output is correct
22	Correct	9 ms	19600 KB	Output is correct
23	Correct	16 ms	19600 KB	Output is correct
24	Correct	13 ms	19600 KB	Output is correct
25	Correct	9 ms	19600 KB	Output is correct
26	Correct	16 ms	19600 KB	Output is correct
27	Correct	13 ms	19600 KB	Output is correct
28	Correct	9 ms	19600 KB	Output is correct
29	Correct	16 ms	19600 KB	Output is correct
30	Correct	16 ms	19600 KB	Output is correct
31	Correct	13 ms	19600 KB	Output is correct
32	Correct	13 ms	19600 KB	Output is correct
33	Correct	16 ms	19600 KB	Output is correct
34	Correct	16 ms	19600 KB	Output is correct
35	Correct	6 ms	19600 KB	Output is correct
36	Correct	6 ms	19600 KB	Output is correct
37	Correct	9 ms	19600 KB	Output is correct
38	Correct	9 ms	19600 KB	Output is correct
39	Correct	16 ms	19600 KB	Output is correct
40	Correct	9 ms	19600 KB	Output is correct
41	Correct	16 ms	19600 KB	Output is correct
42	Correct	13 ms	19600 KB	Output is correct
43	Correct	16 ms	19600 KB	Output is correct
44	Correct	16 ms	19600 KB	Output is correct
45	Correct	16 ms	19600 KB	Output is correct
46	Correct	13 ms	19600 KB	Output is correct
47	Correct	16 ms	19600 KB	Output is correct
48	Correct	16 ms	19600 KB	Output is correct
49	Correct	16 ms	19600 KB	Output is correct
50	Correct	13 ms	19600 KB	Output is correct
51	Correct	16 ms	19600 KB	Output is correct
52	Correct	13 ms	19600 KB	Output is correct
53	Correct	13 ms	19600 KB	Output is correct
54	Correct	9 ms	19600 KB	Output is correct

답안 #26175

Compilation message

Subtask #1 35.0 / 35.0

Subtask #2 65.0 / 65.0

Subtask #1
35.0 / 35.0

Subtask #2
65.0 / 65.0