Submission #514928

#	Time	Username	Problem	Language	Result	Execution time	Memory
514928		kevin	Sails (IOI07_sails)	C++17	5 / 100	92 ms	2528 KiB

sails

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define all(x) x.begin(), x.end()
#define f first
#define s second
#define ca(v) for(auto i:v) cout<<i<<" ";
#define nl cout<<"\n"

const int MAXN = 5e5 + 5;

struct BIT {
    vector<int> f;
    int n;
    void init(int N) { f = vector<int>(N+1, 0); n = N;}
    int lsb(int x) { return x & -x; }
    void update(int p, int v){ 
        while(p <= n){ f[p] += v; p += lsb(p); } 
    }
    int query(int p) { 
        int sum = 0; 
        while (p > 0) { sum += f[p]; p -= lsb(p); } 
        return sum; 
    }
};

int main()
{
    // ios_base::sync_with_stdio(0); cin.tie(0);
    if (fopen("input.in", "r")) freopen("input.in", "r", stdin);
    int n; cin>>n;
    vector<pair<int, int>> ar;
    for(int i=0; i<n; i++){
        int h, k; cin>>h>>k;
        ar.push_back({h, k});
    }
    BIT bit; bit.init(100005);
    sort(ar.begin(), ar.end());
    for(int i=0; i<n; i++){
        int l = 1;
        int r = ar[i].f;
        int v = bit.query(1);
        int a = ar[i].f;
        while(l <= r){
            int m = (l + r) / 2;
            if(bit.query(m) == v){
                a = m;
                l=m+1;
            }
            else r=m-1;
        }
        if(a + ar[i].s > ar[i].f){
            bit.update(a+1, 1);
            bit.update(ar[i].f+1, -1);
            int res = ar[i].s - (ar[i].f - a);
            bit.update(1, 1);
            bit.update(res+1, -1);
        }
        else{
            bit.update(a+1, 1);
            bit.update(a+ar[i].s+1, -1);
        }
        // for(int j=1; j<6; j++) cout<<bit.query(j)<<" ";
        // nl;
    }
    ll tot = 0;
    for(int i=1; i<=100000; i++){
        int x = bit.query(i);
        tot += (ll)x * (x-1) / 2;
    }
    cout<<tot;
}

Compilation message (stderr)

sails.cpp: In function 'int main()':
sails.cpp:31:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |     if (fopen("input.in", "r")) freopen("input.in", "r", stdin);
      |                                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 5
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10
• Subtask 11: 0 / 10