Submission #320682

#	Time	Username	Problem	Language	Result	Execution time	Memory
320682		phathnv	Palindromic Partitions (CEOI17_palindromic)	C++11	100 / 100	57 ms	15076 KiB

palindromic

#include <bits/stdc++.h>

#define mp make_pair
#define X first
#define Y second

using namespace std;

typedef long long ll;
typedef pair <int, int> ii;

const int N = 1e6 + 1;
const int base = 163;

int t, n;
char s[N];
ll pw[N];

void prepare(){
    pw[0] = 1;
    for(int i = 1; i < N; i++)
        pw[i] = pw[i - 1] * base;
}

void readInput(){
    scanf("%s", s + 1);
    n = strlen(s + 1);
}

void solve(){
    int res = 0;
    int l = 1, r = n, len = 0;
    ll hashedL = 0, hashedR = 0;
    while (l < r){
        hashedL = hashedL * base + s[l++];
        hashedR = hashedR + s[r--] * pw[len++];

        if (hashedL == hashedR){
            hashedL = hashedR = 0;
            res += 2;
            len = 0;
        }
    }
    if (hashedL || l <= r)
        res++;
    printf("%d\n", res);
}

int main(){
    scanf("%d", &t);
    prepare();
    while (t--){
        readInput();
        solve();
    }
    return 0;
}

Compilation message (stderr)

palindromic.cpp: In function 'void readInput()':
palindromic.cpp:26:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   26 |     scanf("%s", s + 1);
      |     ~~~~~^~~~~~~~~~~~~
palindromic.cpp: In function 'int main()':
palindromic.cpp:50:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   50 |     scanf("%d", &t);
      |     ~~~~~^~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 20 / 20
• Subtask 3: 25 / 25
• Subtask 4: 40 / 40