Submission #102647

#	Time	Username	Problem	Language	Result	Execution time	Memory
102647		fanache99	Arranging Tickets (JOI17_arranging_tickets)	C++14	0 / 100	3 ms	384 KiB

arranging_tickets

#include <bits/stdc++.h>

using namespace std;

const int SIZE = 1 << 17;
int pointer = SIZE;
char buffer[SIZE];

char Advance() {
    if (pointer == SIZE) {
        fread(buffer, 1, SIZE, stdin);
        pointer = 0;
    }
    return buffer[pointer++];
}

int Read() {
    int answer = 0;
    char ch = Advance();
    while (!isdigit(ch))
        ch = Advance();
    while (isdigit(ch)) {
        answer = answer * 10 + ch - '0';
        ch = Advance();
    }
    return answer;
}

const int MAXN = 200000;
const int MAXM = 100000;
const long long INF = 1000000000000000000LL;

long long sum[1 + MAXN], start[1 + MAXN], finish[1 + MAXN];

bool Check(int n, long long limit) {
    long long add = 0, active = 0, good = 0;
    for (int i = 1; i <= n; i++) {
        good = min(good, active - finish[i]);
        active += sum[i];
        long long need = max(0LL, active + add - limit - 2 * good);
        if (active - good < need)
            return false;
        add += need;
        good += need;
    }
    return add <= limit;
}

int main() {
    //ifstream cin("tema.in");
    //ofstream cout("tema.out");
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        if (a > b)
            swap(a, b);
        sum[a] += c;
        sum[b] -= c;
        start[a] += c;
        finish[b] += c;
    }
    long long left = 0, right = INF, answer;
    while (left <= right) {
        long long middle = (left + right) / 2;
        if (Check(n, middle)) {
            answer = middle;
            right = middle - 1;
        }
        else
            left = middle + 1;
    }
    cout << answer << "\n";
    return 0;
 }

Compilation message (stderr)

arranging_tickets.cpp: In function 'char Advance()':
arranging_tickets.cpp:11:14: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
         fread(buffer, 1, SIZE, stdin);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 35
• Subtask 3: 0 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 15