Submission #666722

#	Time	Username	Problem	Language	Result	Execution time	Memory
666722		omikron123	Job Scheduling (CEOI12_jobs)	C++14	90 / 100	1090 ms	10736 KiB

jobs

// https://oj.uz/problem/view/CEOI12_jobs

#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>

using namespace std;

// n,d<=1e5, m<=1e6
int n, d, m;

struct J {
    int s, idx;
};
J jobs[1000005];

// return if x machine is enough
bool check(int x, bool print) {
    // {deadline, idx}
    priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>> > q;
    int j = 0;  // job index
    for (int i = 1; i <= n; i++) {
        // enqueue job arrivals
        for (; j < m && jobs[j].s == i; j++)
            q.push({i + d, jobs[j].idx});

        // consume jobs in queue
        int cnt = 0;
        while(!q.empty() && cnt < x) {
            int deadline = q.top().first;
            int idx = q.top().second;
            q.pop();
            if (deadline < i)       // already expired
                return false;
            cnt++;
            if (print)
                printf("%d ", idx);
        }
        if (print)
            printf("0\n");
    }
    return true;
}

inline bool cmp(J &a, J &b) {return a.s < b.s;}

inline int read() {
    int r = 0;
    bool start = false, neg = false;
    while (true) {
        char c = getchar();
        if (!start && c != '-' && (c < '0' || c > '9')) continue;
        start = true;
        if (c == '-') neg = true;
        else if (c >= '0' && c <= '9')
            r = r * 10 + c - '0';
        else
            break;
    }
    return r;
}

int main() {
    scanf("%d %d %d", &n, &d, &m);
    for (int i = 0; i < m; i++) {
        jobs[i].s = read();
        jobs[i].idx = i+1;
    }
    sort(jobs, jobs+m, cmp);

    int low = 1, high = m;
    while (low < high) {
        int mid = (low + high) / 2;
        if (check(mid, false))
            high = mid;
        else
            low = mid+1;
    }
    printf("%d\n", low);
    check(low, true);

    return 0;
}

/*
8 2 12
1 2 4 2 1 3 5 6 2 3 6 4

answer is 2
*/

Compilation message (stderr)

jobs.cpp: In function 'int read()':
jobs.cpp:50:25: warning: variable 'neg' set but not used [-Wunused-but-set-variable]
   50 |     bool start = false, neg = false;
      |                         ^~~
jobs.cpp: In function 'int main()':
jobs.cpp:65:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |     scanf("%d %d %d", &n, &d, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 90 / 100