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Submission #13165

# Submission time Handle Problem Language Result Execution time Memory
13165 2015-02-01T11:08:19 Z gs14004 Palindromes (APIO14_palindrome) C++14
47 / 100
 1000 ms 21756 KB 
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;
typedef pair<int,int> pi;

char str[600005];
int n;
int dp[600005];

void manacher(){
    int max_val = 0, pos = 0;
    for (int i=1; i<=n; i++) {
        int ret = i;
        if(max_val >= i){
            ret = min(max_val,i + dp[2 * pos - i]);
        }
        while (ret+1<=n && 2*i-ret-1> 0 && str[ret+1] == str[2*i-ret-1]){
            ret++;
        }
        dp[i] = ret - i;
        if(ret > max_val){
            pos = i, ret = max_val;
        }
    }
    for (int i=1; i<=n; i++) {
        if(i%2 == 0) dp[i]++;
        dp[i] /= 2;
    }
}

const int prime = 811;
const long long mod = 1e15 + 811;
long long hs[300005], pw[300005];

long long gob(long long b1, long long b2){
    long long r = 0;
    while (b1) {
        r += b2 * (b1 & 255);
        b2 <<= 8;
        b1 >>= 8;
        b2 %= mod;
        r %= mod;
    }
    return r;
}

long long get_hash(int s, int e){
    if(s > e) return 0;
    return ((hs[e] - gob(hs[s-1],pw[e - s + 1])) % mod + mod) % mod;
}

unordered_map<long long,int> num;
int piv;

int tpar[300005], tcnt[300005], tlen[300005];
vector<int> graph[300005];
int subsize[300005];
long long ret;

void shrink(int s, int e, long long pa){
    if(s > e) return;
    long long par = 0;
    num[0] = 0;
    int st = 1;
    while (s <= e) {
        long long hsh = get_hash(s,e);
        if(num.find(hsh) != num.end()){
            if(par){
                graph[num[par]].push_back(num[hsh]);
                graph[num[hsh]].push_back(num[par]);
            }
            if(st){
                tcnt[num[hsh]]++;
            }
            break;
        }
        num[hsh] = ++piv;
        if(par){
            graph[num[par]].push_back(num[hsh]);
            graph[num[hsh]].push_back(num[par]);
        }
        if(st){
            tcnt[num[hsh]]++;
            st = 0;
        }
        tlen[num[hsh]] = e - s + 1;
        par = hsh;
        s++;
        e--;
    }
    if(s > e){
        graph[0].push_back(num[par]);
        graph[num[par]].push_back(0);
    }
}

int dfs(int x, int pa){
    int r = tcnt[x];
    for (int i=0; i<graph[x].size(); i++) {
        if(graph[x][i] == pa) continue;
        r += dfs(graph[x][i],x);
    }
    ret = max(ret,1ll * r * tlen[x]);
    return r;
}

int main(){
    scanf("%s",str);
    n = (int)strlen(str);
    for (int i=n-1; i>=0; i--) {
        str[2*i+1] = str[i];
        str[2*i] = ' ';
    }
    n = 2 * n - 1;
    str[0] = 0;
    manacher();
    pw[0] = 1;
    for (int i=1; i<=(n+1)/2; i++) {
        hs[i] = (hs[i-1] * prime + str[2*i-1]) % mod;
        pw[i] = pw[i-1] * prime % mod;
    }
    for (int i=1; i<=n; i++) {
        if(i % 2 == 1){
            shrink((i+1)/2 - dp[i],(i+1)/2 + dp[i],0);
        }
        else{
            shrink(i/2 + 1 - dp[i], i/2 + dp[i],0);
        }
    }
    dfs(0,-1);
    printf("%lld",ret);
}

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 20924 KB Output is correct - answer is '7'
2 Correct 0 ms 20924 KB Output is correct - answer is '4'
3 Correct 0 ms 20924 KB Output is correct - answer is '9'
4 Correct 2 ms 20924 KB Output is correct - answer is '1'
5 Correct 0 ms 20924 KB Output is correct - answer is '1'
6 Correct 4 ms 20924 KB Output is correct - answer is '2'
7 Correct 4 ms 20924 KB Output is correct - answer is '3'
8 Correct 4 ms 20924 KB Output is correct - answer is '3'
9 Correct 0 ms 20924 KB Output is correct - answer is '15'
10 Correct 0 ms 20924 KB Output is correct - answer is '24'
11 Correct 0 ms 20924 KB Output is correct - answer is '10'
12 Correct 0 ms 20924 KB Output is correct - answer is '24'
13 Correct 0 ms 20924 KB Output is correct - answer is '25'
14 Correct 0 ms 20924 KB Output is correct - answer is '28'
15 Correct 4 ms 20924 KB Output is correct - answer is '2'
16 Correct 0 ms 20924 KB Output is correct - answer is '1'
17 Correct 0 ms 20924 KB Output is correct - answer is '15'
18 Correct 4 ms 20924 KB Output is correct - answer is '18'
19 Correct 0 ms 20924 KB Output is correct - answer is '1176'
20 Correct 0 ms 20924 KB Output is correct - answer is '1225'
21 Correct 4 ms 20924 KB Output is correct - answer is '136'
22 Correct 0 ms 20924 KB Output is correct - answer is '45'
23 Correct 0 ms 20924 KB Output is correct - answer is '2500'
24 Correct 0 ms 20924 KB Output is correct - answer is '380'
25 Correct 0 ms 20924 KB Output is correct - answer is '2304'
26 Correct 3 ms 20924 KB Output is correct - answer is '110'
27 Correct 0 ms 20924 KB Output is correct - answer is '93'
28 Correct 3 ms 20924 KB Output is correct - answer is '729'
29 Correct 0 ms 20924 KB Output is correct - answer is '132'
30 Correct 0 ms 20924 KB Output is correct - answer is '7'
31 Correct 0 ms 20924 KB Output is correct - answer is '8'
32 Correct 0 ms 20924 KB Output is correct - answer is '64'

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 20924 KB Output is correct - answer is '124251'
2 Correct 5 ms 20924 KB Output is correct - answer is '38226'
3 Correct 0 ms 20924 KB Output is correct - answer is '249500'
4 Correct 2 ms 20924 KB Output is correct - answer is '5778'
5 Correct 0 ms 20924 KB Output is correct - answer is '247506'
6 Correct 0 ms 20924 KB Output is correct - answer is '248004'
7 Correct 2 ms 20924 KB Output is correct - answer is '973'
8 Correct 4 ms 20924 KB Output is correct - answer is '123753'
9 Correct 4 ms 20924 KB Output is correct - answer is '2346'
10 Correct 4 ms 20924 KB Output is correct - answer is '53'
11 Correct 0 ms 20924 KB Output is correct - answer is '52'
12 Correct 4 ms 20924 KB Output is correct - answer is '976'

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 79 ms 21756 KB Output is correct - answer is '12497500'
2 Correct 47 ms 21672 KB Output is correct - answer is '6481800'
3 Correct 149 ms 21756 KB Output is correct - answer is '25000000'
4 Correct 111 ms 21716 KB Output is correct - answer is '17816841'
5 Correct 7 ms 21700 KB Output is correct - answer is '9945'
6 Correct 15 ms 21652 KB Output is correct - answer is '504100'
7 Correct 22 ms 21572 KB Output is correct - answer is '1512930'
8 Correct 0 ms 20924 KB Output is correct - answer is '413'
9 Correct 5 ms 20924 KB Output is correct - answer is '428'
10 Correct 0 ms 21384 KB Output is correct - answer is '7232'

Subtask #4
0.0 / 26.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1000 ms 20920 KB Program timed out
2 Halted 0 ms 0 KB -

Subtask #5
0.0 / 27.0

# Verdict Execution time Memory Grader output
1 Halted 0 ms 0 KB -