Submission #554418

#	Time	Username	Problem	Language	Result	Execution time	Memory
554418		Ronin13	Let's Win the Election (JOI22_ho_t3)	C++14	10 / 100	399 ms	2328 KiB

Main

#include<bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define pii pair<int,int>
#define pll pair<ll,ll>
#define ull unsigned ll
#define pb push_back
#define epb emplace_back
using namespace std;

const double inf = 1e9 + 1;

int main(){
    int n; cin >> n;
    int k; cin >> k;
    pair<double, double> a[n + 1];
    for(int i = 1; i <= n; i++){
        cin >> a[i].s >> a[i].f;
        if(a[i].f == -1) a[i].f = inf;
    }
    sort(a + 1, a + 1 + n);
    for(int i = 1; i <= n; i++){
        //cout << a[i].f << ' ' << a[i].s << "\n";
    }
    double ans = inf;
    for(int x = 0; x <= n; x++){
        double dp[n + 1][n + 1];
        for(int i = 0; i <= n; i++){
            for(int j = 0; j <= n; j++) dp[i][j] = inf;
        }
        dp[0][0] = 0;
        for(int i = 1; i <= n; i++){
            for(int j = 0; j <= n; j++){
                if(j > 0)dp[i][j] =min(dp[i][j], dp[i - 1][j - 1] + a[i].f / j);
                dp[i][j] = min(dp[i][j], dp[i - 1][j] + a[i].s / (x + 1));
            }
        }
        double cursum = 0;
        multiset <pair<double, int> > st;
        for(int i = 1; i <= n; i++){
            cursum += a[i].s;
            st.insert({a[i].s, i});
        }
        while(st.size() > k) {
            cursum -= st.rbegin() -> f;
            st.erase(st.find(*st.rbegin()));
        }
        for(int i = 1; i <= n; i++){
            double cur = dp[i - 1][x];
            cur += cursum / (x + 1);
            if(ans > cur){
                //cout << dp[i - 1][x] << "\n";
                //cout << x << ' ' << i;
                //cout << "\n";
                ans = cur;
            }
            multiset <pair<double, int> > :: iterator it = st.find({a[i].s, i});
            if(it != st.end()){
                cursum -= a[i].s;
                st.erase({a[i].s, i});
            }
            if(st.size() > k - i && !st.empty()){
                cursum -= st.rbegin() -> f;
                st.erase(st.find(*st.rbegin()));
            }
        }
    }
    cout << fixed << setprecision(3) << ans;
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:45:25: warning: comparison of integer expressions of different signedness: 'std::multiset<std::pair<double, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   45 |         while(st.size() > k) {
      |               ~~~~~~~~~~^~~
Main.cpp:63:26: warning: comparison of integer expressions of different signedness: 'std::multiset<std::pair<double, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   63 |             if(st.size() > k - i && !st.empty()){
      |                ~~~~~~~~~~^~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 11
• Subtask 4: 0 / 12
• Subtask 5: 0 / 33
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23