Submission #1027220

#	Time	Username	Problem	Language	Result	Execution time	Memory
1027220		vjudge1	Sure Bet (CEOI17_sure)	C++17	100 / 100	81 ms	6540 KiB

sure

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define ld long double
#define pb push_back
#define pf push_front
#define vi vector<ll>
#define vii vector<vi>
#define pll pair<ll, ll>
#define vpll vector<pll>
#define all(a) a.begin(), a.end()
#define fi first
#define se second
using namespace std;
const ll mod = 1e9 + 7;
const ll inf = 2e18;
const ll blocksz = 320;
const ll N = 1e5 + 8;
ld a[N],b[N],preA[N],preB[N];
ll n;
void solve(){
    cin >> n;
    for(ll i = 1; i <= n; i++) cin >> a[i] >> b[i];
    sort(a+1,a+n+1,greater<ld>());
    sort(b+1,b+n+1,greater<ld>());
    for(ll i = 1; i <= n; i++){
        preA[i] = preA[i-1]+a[i];
        preB[i] = preB[i-1]+b[i];
    }
    ld ans = 0;
    for(ll i = 1; i <= n; i++){
        ll l = 1, r = n;
        ll pos = -1;
        while(l <= r){
            ll m = l+r>>1;
            if(preB[m] >= preA[i]){
                r = m-1;;
                pos = m;
            }
            else l = m+1;;
        }
        if(pos == -1) continue;
        ans = max(ans,preA[i]-(ld)i-(ld)pos);
    }
    for(ll i = 1; i <= n; i++){
        ll l = 1, r = n;
        ll pos = -1;
        while(l <= r){
            ll m = l+r>>1;
            if(preA[m] >= preB[i]){
                r = m-1;;
                pos = m;
            }
            else l = m+1;;
        }
        if(pos == -1) continue;
        ans = max(ans,preB[i]-i-pos);
    }
    cout << setprecision(4) << fixed << ans;
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen("test.inp", "r")){
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll T = 1;
    // cin >> T;
    for (ll i = 1; i <= T; i++){
        solve();
        cout << '\n';
    }
}

Compilation message (stderr)

sure.cpp: In function 'void solve()':
sure.cpp:35:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   35 |             ll m = l+r>>1;
      |                    ~^~
sure.cpp:49:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   49 |             ll m = l+r>>1;
      |                    ~^~
sure.cpp: In function 'int main()':
sure.cpp:66:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sure.cpp:67:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 40 / 40