Submission #1106640

#	Time	Username	Problem	Language	Result	Execution time	Memory
1106640		Canuc80k	Potatoes and fertilizers (LMIO19_bulves)	C++17	100 / 100	99 ms	23240 KiB

bulves

#include "bits/stdc++.h"
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;

const ll N = 1e6 + 1;

ll n;
ll a[N], b[N];

namespace sub1 {
    const ll N = 1e6 + 1;
    ll f[N];

    void solve() {
        ll res = 0;
        for (int i = 1; i <= n; i ++) f[i] = f[i - 1] + (a[i] - b[i]);
        for (int i = 1; i <= n; i ++) res += abs(f[i]);
        cout << res;
    }
}

namespace sub3 {
    const ll N = 3e3 + 1;
    ll d[N];
    ll f[(ll)3e4 + 1], of[(ll)3e4 + 1];

    void solve() {
        for (int i = 1; i <= n; i ++) d[i] = d[i - 1] + a[i] - b[i];
        memset(f, 0x3f, sizeof f);
        
        of[0] = 0;
        for (int i = 1; i <= n; i ++) {
            for (int j = 0; j <= d[n]; j ++) {
                if (j != 0) f[j] = f[j - 1];
                f[j] = min(f[j], of[j] + abs(d[i] - j)); 
            }
            for (int j = 0; j <= d[n]; j ++) {
                of[j] = f[j];
                f[j] = 1e18;
            }
        }
        cout << of[d[n]];
    }
}

namespace sub5 {
    const ll N = 1e6 + 1;
    ll d[N];

    void solve() {
        for (int i = 1; i <= n; i ++) {
            d[i] = d[i - 1] + a[i] - b[i];
        }

        priority_queue<ll> pq; ll res = 0;
        for (int i = 1; i <= n; i ++) {
            if (d[i] < 0) res += -d[i], d[i] = 0;
            if (d[i] >= d[n]) res += d[i] - d[n], d[i] = d[n];
            
            pq.push(d[i]); ll top = pq.top();
            if (pq.top() > d[i]) {
                res += top - d[i];
                pq.pop(); pq.push(d[i]);
            }
        }
        cout << res;
    }
}

void doTest(ll testID) {
    cin >> n; ll sa = 0, sb = 0;
    for (int i = 1; i <= n; i ++) {
        cin >> a[i] >> b[i];
        sa += a[i], sb += b[i];
    }
    
    if (sa == sb) {sub1::solve(); return;}
    if (n <= 3e3 && max(sa, sb) <= 3e4) {sub3::solve(); return;}
    sub5::solve();
}

signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0);

    int test = 1; 
    // cin >> test;
    for (int _ = 1; _ <= test; _ ++) doTest(_);
}

• Subtask 1: 24 / 24
• Subtask 2: 10 / 10
• Subtask 3: 20 / 20
• Subtask 4: 10 / 10
• Subtask 5: 36 / 36