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Submission #47583

# Submission time Handle Problem Language Result Execution time Memory
47583 2018-05-05T06:39:16 Z TAMREF Palindromes (APIO14_palindrome) C++11
23 / 100
 1000 ms 59540 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;

        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;
            }

            flag_once = 0;

            if(child_i != -1){
                gph[tmp_i].push_back(child_i);
                isRoot[child_i] = 0;
            }
            if(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 19064 KB Output is correct
2 Correct 20 ms 19180 KB Output is correct
3 Correct 20 ms 19372 KB Output is correct
4 Correct 21 ms 19372 KB Output is correct
5 Correct 20 ms 19372 KB Output is correct
6 Correct 20 ms 19372 KB Output is correct
7 Correct 20 ms 19372 KB Output is correct
8 Correct 20 ms 19380 KB Output is correct
9 Correct 21 ms 19380 KB Output is correct
10 Correct 20 ms 19380 KB Output is correct
11 Correct 20 ms 19380 KB Output is correct
12 Correct 21 ms 19380 KB Output is correct
13 Correct 21 ms 19384 KB Output is correct
14 Correct 20 ms 19384 KB Output is correct
15 Correct 20 ms 19384 KB Output is correct
16 Correct 21 ms 19384 KB Output is correct
17 Correct 20 ms 19428 KB Output is correct
18 Correct 22 ms 19428 KB Output is correct
19 Correct 21 ms 19428 KB Output is correct
20 Correct 21 ms 19428 KB Output is correct
21 Correct 21 ms 19428 KB Output is correct
22 Correct 21 ms 19428 KB Output is correct
23 Correct 22 ms 19428 KB Output is correct
24 Correct 21 ms 19428 KB Output is correct
25 Correct 22 ms 19428 KB Output is correct
26 Correct 21 ms 19428 KB Output is correct
27 Correct 20 ms 19428 KB Output is correct
28 Correct 21 ms 19428 KB Output is correct
29 Correct 21 ms 19428 KB Output is correct
30 Correct 21 ms 19428 KB Output is correct
31 Correct 20 ms 19428 KB Output is correct
32 Correct 21 ms 19428 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 51 ms 20836 KB Output is correct
2 Correct 35 ms 20836 KB Output is correct
3 Correct 81 ms 22168 KB Output is correct
4 Correct 25 ms 22168 KB Output is correct
5 Correct 83 ms 22168 KB Output is correct
6 Correct 81 ms 22168 KB Output is correct
7 Correct 21 ms 22168 KB Output is correct
8 Correct 51 ms 22168 KB Output is correct
9 Correct 24 ms 22168 KB Output is correct
10 Correct 21 ms 22168 KB Output is correct
11 Correct 21 ms 22168 KB Output is correct
12 Correct 22 ms 22168 KB Output is correct

Subtask #3
0 / 24.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1084 ms 57432 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 1082 ms 57996 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 1080 ms 59540 KB Time limit exceeded
2 Halted 0 ms 0 KB -