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Submission #154316

# Submission time Handle Problem Language Result Execution time Memory
154316 2019-09-20T12:45:18 Z arnold518 Palindromic Partitions (CEOI17_palindromic) C++14
100 / 100
 239 ms 34644 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 1e6;
const ll MOD = 1e9+7;
const ll P = 31;

int TC, N, ans;
char S[MAXN+10];
ll ppow[MAXN+10], ipow[MAXN+10], H[MAXN+10];

ll mypow(ll x, ll y)
{
    if(y==0) return 1;
    if(y%2) return mypow(x, y-1)*x%MOD;
    ll t=mypow(x, y/2);
    return t*t%MOD;
}

ll calc(int l, int r)
{
    ll t=H[r]-H[l-1]; t%=MOD;
    if(t<0) t+=MOD;
    t*=ipow[l]; t%=MOD;
    return t;
}

int main()
{
    int i, j;

    ppow[0]=1; ipow[0]=1; ipow[1]=mypow(P, MOD-2);
    for(i=1; i<=MAXN; i++) ppow[i]=ppow[i-1]*P%MOD;
    for(i=2; i<=MAXN; i++) ipow[i]=ipow[i-1]*ipow[1]%MOD;

    scanf("%d", &TC);
    while(TC--)
    {
        scanf("%s", S+1);
        N=strlen(S+1); ans=0;

        for(i=1; i<=N; i++) H[i]=(S[i]-'a'+1)*ppow[i]%MOD;
        for(i=1; i<=N; i++) H[i]=(H[i-1]+H[i])%MOD;

        int it=1;
        for(i=1; i<=N/2; i++) if(calc(it, i)==calc(N-i+1, N-it+1))
        {
            //printf("!%d\n", i);
            ans+=2;
            it=i+1;
        }
        if(N%2 || it!=N/2+1) ans++;
        printf("%d\n", ans);
    }
}

Compilation message

palindromic.cpp: In function 'int main()':
palindromic.cpp:34:12: warning: unused variable 'j' [-Wunused-variable]
     int i, j;
            ^
palindromic.cpp:40:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &TC);
     ~~~~~^~~~~~~~~~~
palindromic.cpp:43:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%s", S+1);
         ~~~~~^~~~~~~~~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 15992 KB Output is correct
2 Correct 26 ms 15912 KB Output is correct
3 Correct 26 ms 15992 KB Output is correct
4 Correct 26 ms 15992 KB Output is correct
5 Correct 29 ms 15992 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 15992 KB Output is correct
2 Correct 26 ms 15912 KB Output is correct
3 Correct 26 ms 15992 KB Output is correct
4 Correct 26 ms 15992 KB Output is correct
5 Correct 29 ms 15992 KB Output is correct
6 Correct 26 ms 15992 KB Output is correct
7 Correct 27 ms 15996 KB Output is correct
8 Correct 26 ms 15992 KB Output is correct
9 Correct 26 ms 15992 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 15992 KB Output is correct
2 Correct 26 ms 15912 KB Output is correct
3 Correct 26 ms 15992 KB Output is correct
4 Correct 26 ms 15992 KB Output is correct
5 Correct 29 ms 15992 KB Output is correct
6 Correct 26 ms 15992 KB Output is correct
7 Correct 27 ms 15996 KB Output is correct
8 Correct 26 ms 15992 KB Output is correct
9 Correct 26 ms 15992 KB Output is correct
10 Correct 28 ms 16220 KB Output is correct
11 Correct 28 ms 16088 KB Output is correct
12 Correct 28 ms 16164 KB Output is correct
13 Correct 28 ms 16108 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 15992 KB Output is correct
2 Correct 26 ms 15912 KB Output is correct
3 Correct 26 ms 15992 KB Output is correct
4 Correct 26 ms 15992 KB Output is correct
5 Correct 29 ms 15992 KB Output is correct
6 Correct 26 ms 15992 KB Output is correct
7 Correct 27 ms 15996 KB Output is correct
8 Correct 26 ms 15992 KB Output is correct
9 Correct 26 ms 15992 KB Output is correct
10 Correct 28 ms 16220 KB Output is correct
11 Correct 28 ms 16088 KB Output is correct
12 Correct 28 ms 16164 KB Output is correct
13 Correct 28 ms 16108 KB Output is correct
14 Correct 239 ms 34644 KB Output is correct
15 Correct 145 ms 29888 KB Output is correct
16 Correct 219 ms 34012 KB Output is correct
17 Correct 133 ms 25848 KB Output is correct