제출 #1210402

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1210402		CodeLakVN	Cigle (COI21_cigle)	C++20	100 / 100	174 ms	98548 KiB

cigle

#include <bits/stdc++.h>
using namespace std;

#define task "main"
#define no "NO"
#define yes "YES"
#define F first
#define S second
#define vec vector
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)

template<class X, class Y>
    bool maximize(X &x, Y y) {
        if (x < y) {
            x = y;
            return true;
        }
        return false;
    }

const int MAX_N = (int)5e3 + 5;

int n;
int a[MAX_N];

namespace sub4 {
    const int MAX_N = 505;

    int dp[MAX_N][MAX_N];

    bool mark[MAX_N * 5000];

    void solve() {
        memset(dp, 0, sizeof(dp));
        FOR(l, 2, n) {
            int curLength = 0;
            FOR(r, l, n) {
                int preLength = 0, res = 0;
                FOD(i, l - 1, 1) {
                    if (mark[preLength]) res++;
                    maximize(dp[l][r], dp[i][l - 1] + res);
                    preLength += a[i];
                }
                curLength += a[r];
                mark[curLength] = 1;
            }
            FOD(r, n, l) {
                mark[curLength] = 0;
                curLength -= a[r];
            }
        }
        int ans = 0;
        FOR(l, 1, n) maximize(ans, dp[l][n]);
        cout << ans << "\n";
    }
}

namespace sub5 {
    int dp[MAX_N][MAX_N];
    int f[MAX_N], sum[MAX_N];
    
    void solve() {
        memset(dp, 0, sizeof(dp));
        sum[0] = 0;
        FOR(i, 1, n) sum[i] = sum[i - 1] + a[i];
        
        FOR(l, 2, n) {
            f[0] = INT_MIN;
            FOR(i, 1, l - 1) f[i] = max(f[i - 1], dp[i][l - 1]);

            int i = l - 2, cnt = 0, res = 0;
            FOR(r, l, n) {
                dp[l][r] = res;
                while (i > 0 && sum[r] + sum[i] > 2 * sum[l - 1]) i--;
                if (i > 0 && sum[r] + sum[i] == 2 * sum[l - 1]) maximize(res, f[i] + (++cnt));
            }
        }

        int ans = 0;
        FOR(l, 1, n) maximize(ans, dp[l][n]);
        cout << ans << "\n";
    }  
}

void solve() {
    cin >> n;
    FOR(i, 1, n) cin >> a[i];

    // if (n <= 500) sub4::solve();
    sub5::solve();
}

int32_t main() {
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    bool multitest = 0;
    int numTest = 1;
    if (multitest) cin >> numTest;

    while (numTest--) {
        solve();
    }

    return 0;
}

/* Lak lu theo dieu nhac!!!! */

컴파일 시 표준 에러 (stderr) 메시지

cigle.cpp: In function 'int32_t main()':
cigle.cpp:101:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
cigle.cpp:102:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 13 / 13
• Subtask 4: 15 / 15
• Subtask 5: 52 / 52