Submission #900641

#	Time	Username	Problem	Language	Result	Execution time	Memory
900641		LucaIlie	Fish 2 (JOI22_fish2)	C++17	0 / 100	2834 ms	3136 KiB

fish2

#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 1e5;
int v[MAX_N + 1], leftt[MAX_N + 1], rightt[MAX_N + 1];
bool baul[MAX_N + 1], baur[MAX_N + 1];
long long s[MAX_N + 1];

int main() {
    int n;

    cin >> n;
    for ( int i = 1; i <= n; i++ ) {
        cin >> v[i];
        s[i] = s[i - 1] + v[i];
    }

    for ( int i = 1; i < n; i++ ) {
        int l = 0, r = i + 1;
        while ( r - l > 1 ) {
            int mid = (l + r) / 2;
            if ( s[i] - s[mid - 1] >= v[i + 1] )
                l = mid;
            else
                r = mid;
        }
        leftt[i] = l;
    }

    for ( int i = 2; i <= n; i++ ) {
        int l = i - 1, r = n + 1;
        while ( r - l > 1 ) {
            int mid = (l + r) / 2;
            if ( s[mid] - s[i - 1] >= v[i - 1] )
                r = mid;
            else
                l = mid;
        }
        rightt[i] = r;
    }

    for ( int i = 1; i < n; i++ ) {
        if ( leftt[i] == 0 )
            baul[i] = 0;
        else
            baul[i] = (rightt[leftt[i]] <= i);
    }

    for ( int i = 2; i <= n; i++ ) {
        if ( rightt[i] == n + 1 )
            baur[i] = 0;
        else
            baur[i] = (leftt[rightt[i]] >= i);
    }

    int ans = 0;
    for ( int i = 1; i <= n; i++ ) {
        int p;

        p = i;
        while ( p >= 2 && (rightt[p] <= i || baur[p]) )
            p--;

        if ( p != 1 )
            continue;

        p = n;
        while ( p <= n - 1 && (leftt[p] >= i || baul[p]) )
            p++;

        if ( p == n )
            ans++;
    }

    cout << ans;

    return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 12
• Subtask 4: 0 / 23
• Subtask 5: 0 / 35
• Subtask 6: 0 / 17