oj.uz

Submission #47584

# Submission time Handle Problem Language Result Execution time Memory
47584 2018-05-05T06:42:44 Z TAMREF Palindromes (APIO14_palindrome) C++11
23 / 100
 1000 ms 24500 KB 
#include <bits/stdc++.h>
//#define TAMREF 1
using namespace std;

typedef long long ll;

const char g = 'a' + 26;
const ll o = 28LL;
const ll h[2] = {1000000007LL, 1610612741LL};
const ll io[2] = {35714286LL, 1323003323LL};
const int mx = 6e5 + 5;



ll ph[2][mx], iph[2][mx];

void init_hash(){
    for(int b = 0; b < 2; b++){
        ph[b][0] = 1;
        iph[b][0] = 1;
        for(int i = 1; i < mx; i++){
            ph[b][i] = ph[b][i-1] * o % h[b];
            iph[b][i] = iph[b][i-1] * io[b] % h[b];
        }
    }
}

char S[mx], P[mx];
int n, m;

void input(){
    scanf("%s",P); m = strlen(P);
    for(int i = 0; i < m; i++){
        S[2*i] = g;
        S[2*i+1] = P[i];
    }
    S[2*m] = g;
    n = 2 * m + 1;
}

int R[mx];

void Manacher(){
    int r = 0, j = 0;
    for(int i = 1; i < n; i++){
        int &h = R[i];
        if(i <= r) h = min(r - i, R[2*j - i]);
        while(i-h-1 >= 0 && i+h+1 < n && S[i-h-1] == S[i+h+1]) ++h;
        if(i + h > r){
            j = i;
            r = i + h;
        }
    }
    #ifdef TAMREF
    puts(S);
    for(int i = 0; i < n; i++) printf("%d ",R[i]);
    puts("");
    #endif
}

unordered_map<ll,int> I;
vector<int> cnt(1);
vector<int> len(1);
vector<vector<int>> gph(1);
vector<int> isRoot(1);

inline ll enc(ll *h){
    return h[0] << 32 | h[1];
}

void Shrink(){
    for(int i = 0; i < n; i++) S[i] -= 'a'-1;

    for(int i = 1, s, e; i < n-1; i++){
        if(!R[i]) continue;
        s = i - R[i] + 1, e = i + R[i] - 1;

        ll hv[2] = {0,0}, tmp;
        int child_i = -1;
        int tmp_i;
        int flag_once = 1, keep_loop = 1;

        for(int b = 0; b < 2; b++){
            for(int j = s; j <= e; j++){
                hv[b] = (hv[b] * o + S[j]) % h[b];
            }
        }

        while(e >= s){
            tmp = enc(hv);
            tmp_i = I[tmp];
            if(!tmp_i){ //insert new hash value
                #ifdef TAMREF
                printf("%d-th HASH : [%d, %d],\nhash string = ",cnt.size(),s,e);
                for(int j = s; j <= e; j++) printf("%c",S[j] + 'a' - 1);
                puts("");
                #endif // TAMREF
                tmp_i = I[tmp] = cnt.size();
                cnt.push_back(flag_once);
                len.push_back((e-s)/2 + 1);
                gph.push_back(vector<int>());
                isRoot.push_back(1);
            }else{
                cnt[tmp_i] += flag_once;
                keep_loop = 0;
            }

            flag_once = 0;

            if(child_i != -1){
                gph[tmp_i].push_back(child_i);
                isRoot[child_i] = 0;
            }

            if(!keep_loop || e - 2 < s + 2) break;

            child_i = tmp_i;
            for(int b = 0; b < 2; b++){
                hv[b] -= S[e] + o * S[e-1];
                hv[b] -= (ph[b][e-s] * S[s] + ph[b][e-s-1] * S[s+1]) % h[b];
                hv[b] = ((hv[b] % h[b] + h[b]) % h[b]) * iph[b][2] % h[b];
            }
            e -= 2;
            s += 2;
        }
    }
}

int vis[mx];
ll ans = 1;

int dfs(int x){
    #ifdef TAMREF
    printf("dfs : %d\n",x);
    #endif // TAMREF
    ll c = cnt[x];
    vis[x] = 1;
    for(int &u : gph[x]){
        if(!vis[u]) c += dfs(u);
    }
    ans = max(ans, c * len[x]);
    return c;
}

void pro(){
    int N = cnt.size();
    for(int i = 1; i < N; i++){
        #ifdef TAMREF
        printf("%d - th node : cnt = %d, len = %d, isRoot = %d\n",i,cnt[i],len[i],isRoot[i]);
        #endif // TAMREF
        if(isRoot[i] && !vis[i]){
            #ifdef TAMREF
            printf("dfs start on %d\n",i);
            #endif // TAMREF
            dfs(i);
        }
    }
    printf("%lld\n",ans);
}

int main(){
    init_hash();
    input();
    Manacher();
    Shrink();
    pro();
}

Compilation message

palindrome.cpp: In function 'void input()':
palindrome.cpp:32:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s",P); m = strlen(P);
     ~~~~~^~~~~~~~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 19192 KB Output is correct
2 Correct 21 ms 19296 KB Output is correct
3 Correct 21 ms 19296 KB Output is correct
4 Correct 22 ms 19296 KB Output is correct
5 Correct 22 ms 19296 KB Output is correct
6 Correct 25 ms 19296 KB Output is correct
7 Correct 21 ms 19296 KB Output is correct
8 Correct 21 ms 19296 KB Output is correct
9 Correct 21 ms 19296 KB Output is correct
10 Correct 21 ms 19296 KB Output is correct
11 Correct 21 ms 19296 KB Output is correct
12 Correct 21 ms 19296 KB Output is correct
13 Correct 21 ms 19296 KB Output is correct
14 Correct 22 ms 19296 KB Output is correct
15 Correct 21 ms 19336 KB Output is correct
16 Correct 21 ms 19336 KB Output is correct
17 Correct 21 ms 19352 KB Output is correct
18 Correct 21 ms 19360 KB Output is correct
19 Correct 21 ms 19360 KB Output is correct
20 Correct 21 ms 19360 KB Output is correct
21 Correct 21 ms 19404 KB Output is correct
22 Correct 21 ms 19404 KB Output is correct
23 Correct 21 ms 19404 KB Output is correct
24 Correct 21 ms 19404 KB Output is correct
25 Correct 21 ms 19404 KB Output is correct
26 Correct 21 ms 19404 KB Output is correct
27 Correct 21 ms 19404 KB Output is correct
28 Correct 21 ms 19404 KB Output is correct
29 Correct 21 ms 19404 KB Output is correct
30 Correct 21 ms 19404 KB Output is correct
31 Correct 21 ms 19404 KB Output is correct
32 Correct 21 ms 19412 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 19556 KB Output is correct
2 Correct 27 ms 19556 KB Output is correct
3 Correct 45 ms 19564 KB Output is correct
4 Correct 23 ms 19564 KB Output is correct
5 Correct 45 ms 19564 KB Output is correct
6 Correct 45 ms 19564 KB Output is correct
7 Correct 21 ms 19564 KB Output is correct
8 Correct 34 ms 19564 KB Output is correct
9 Correct 22 ms 19564 KB Output is correct
10 Correct 21 ms 19564 KB Output is correct
11 Correct 21 ms 19564 KB Output is correct
12 Correct 21 ms 19564 KB Output is correct

Subtask #3
0 / 24.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1077 ms 20732 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
0 / 26.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1084 ms 22252 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #5
0 / 27.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1076 ms 24500 KB Time limit exceeded
2 Halted 0 ms 0 KB -