Submission #1119056

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119056		lam280407	Line Town (CCO23_day1problem3)	C++17	0 / 25	2 ms	340 KiB

Main

#include<bits/stdc++.h>
#define int long long
#define vi vector<int>
#define pii pair<int, int>
#define fi first
#define se second
#define bit(n, i) ((n >> i) & 1)
#define inf 0x3f3f3f3f3f3f3f3f
#define all(x) (x).begin(), (x).end()
#define el '\n'
#define TASK "bai3"
using namespace std;
const int N = 1e6 + 6;
int n, a[N];


namespace sub1{
    int ans = inf;
    void init(){
        for (int i = 1; i <= n; ++i){
            bool ok = true;
            int res = 0, sum = 0;
            for (int j = 1; j <= i; ++j){
                if (!ok) break;
                if (a[j] > 0) ++res;
                else{
                    sum += res;
                    if (res & 1) ok = false;
                    res = 0;
                }
            }
            sum += res;
            if (res & 1) ok = false;
            if (!ok) continue;
            res = 0;
            for (int j = i + 1; j <= n; ++j){
                if (!ok) break;
                if (a[j] < 0) ++res;
                else{
                    sum += res;
                    if (res & 1) ok = false;
                    res = 0;
                }
            }
            sum += res;
            if (res & 1) ok = false;
            if (!ok) continue;
            ans = min(ans, sum >> 1);
        }
        cout << (ans == inf ? -1 : ans);
    }
}


void solve(){
    cin >> n;
    int mn = inf, mx = -inf;
    for (int i = 1; i <= n; ++i){
        cin >> a[i];
        mx = max(mx, a[i]);
        mn = min(mn, a[i]);
    }
    if (n <= 2000 && mn == -1 && mx == 1) sub1::init();
}

void file(){
    if (fopen(TASK".inp", "r")){
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }
}


signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    file();
    solve();
}

Compilation message (stderr)

Main.cpp: In function 'void file()':
Main.cpp:68:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:69:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 3
• Subtask 2: 0 / 3
• Subtask 3: 0 / 3
• Subtask 4: 0 / 4
• Subtask 5: 0 / 4
• Subtask 6: 0 / 3
• Subtask 7: 0 / 2
• Subtask 8: 0 / 3