Submission #549713

#	Time	Username	Problem	Language	Result	Execution time	Memory
549713		cpp219	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	741 ms	3916 KiB

Main

#include<bits/stdc++.h>
#define ll long long
#define ld long double
#define fs first
#define sc second
#define debug(y) cout<<y,exit(0)
using namespace std;
typedef pair<ll,ll> LL;
const ll N = 500 + 9;
const ll inf = 1e18 + 7;

ld ans = inf*1.0,dp[N][N];
ll n,k,collab;
LL a[N];

bool lf(LL x,LL y){
    return x.sc < y.sc;
}

ld cal(ll mid){
    for (ll i = 1;i <= n;i++)
        for (ll j = 0;j <= i;j++){
            dp[i][j] = inf;
            if (i - j - 1 >= mid) dp[i][j] = dp[i - 1][j];
            else dp[i][j] = dp[i - 1][j] + (ld)a[i].sc/((ld)i - j);
            if (j) dp[i][j] = min(dp[i][j],dp[i - 1][j - 1] + (ld)a[i].fs/((ld)mid + 1));
        }
    ld tmp = inf;
    for (ll i = k - mid;i <= n;i++)
        if (n - i >= mid) tmp = min(tmp,dp[n][i]);
    return tmp;
}

int main(){
    ios_base::sync_with_stdio(NULL); cin.tie(0); cout.tie(0);
    #define task "test"
    if (fopen(task".inp","r")){
        freopen(task".inp","r",stdin);
        //freopen(task".out","w",stdout);
    }
    cin>>n>>k;
    for (ll i = 1;i <= n;i++){
        cin>>a[i].fs>>a[i].sc;
        collab += (a[i].sc != -1);
        if (a[i].sc == -1) a[i].sc = inf;
    }
    sort(a + 1,a + n + 1,lf);
    for (ll i = 0;i <= min(k,collab);i++) ans = min(ans,cal(i));
    cout<<fixed<<setprecision(6)<<ans; return 0;
    ll l = 0,h = min(k,collab);
    while(l <= h){
        ll mid = (l + h)/2;
        if (cal(mid) < cal(mid + 1)) h = mid - 1;
        else l = mid + 1;
    }
    //debug(h);
    cout<<fixed<<setprecision(6)<<cal(l);
}
/// be confident

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:38:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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