Submission #519729

# Submission time Handle Problem Language Result Execution time Memory
519729 2022-01-27T07:42:35 Z XII Sails (IOI07_sails) C++17
100 / 100
183 ms 3336 KB
#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define fi first
#define se second
#define mp make_pair
#define eb emplace_back
#define ALL(x) (x).begin(), (x).end()

#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define FORU(i, a, b) for(int i = (a); i <= (b); ++i)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)

#define IOS cin.tie(0)->sync_with_stdio(false);
#define PROB "IOI07_sails"
void Fi(){
    if(fopen(PROB".inp", "r")){
        freopen(PROB".inp", "r", stdin);
        freopen(PROB".out", "w", stdout);
    }
}

const int N = 1e5 + 1;
int n;
using pi = pair<int, int>;
vector<pi> a;

ll bit[2][N];
void update(const int &t, int i, const ll &v){
    while(i < N){
        bit[t][i] += v;
        i += i & -i;
    }
}
ll getSum(const int &t, int i){
    ll ans = 0;
    while(1 <= i){
        ans += bit[t][i];
        i -= i & -i;
    }
    return ans;
}

void updRange(const int &i, const ll &v){
    update(0, 1, v);
    update(0, i + 1, -v);
    update(1, i + 1, v * i);
}

void updRange(const int &l, const int &r, const ll &v){
    updRange(l - 1, -v);
    updRange(r, v);
}

ll query(const int &i){
    return getSum(0, i) * i + getSum(1, i);
}

ll query(const int &l, const int &r){
    return query(r) - query(l - 1);
}

int main(){
    IOS;
    Fi();
    cin >> n; a.resize(n);
    for(pi &x: a) cin >> x.fi >> x.se;
    sort(ALL(a));
    for(auto [H, K]: a){
        int P = H - K + 1;
        int l, r, A = P, B = P;
        for(l = 2, r = P; l <= r; ){
            int mid = (l + r) / 2;
            if(query(mid, P) == 0){
                A = mid - 1;
                r = mid - 1;
            } else l = mid + 1;
        }
        for(l = P + 1, r = H; l <= r; ){
            int mid = (l + r) / 2;
            if(query(P + 1, mid) == 0){
                B = mid;
                l = mid + 1;
            } else r = mid - 1;
        }
        if(A == P){
            updRange(A, A, 1);
            updRange(H + 1, H + 1, -1);
        } else{
            updRange(B + 1, B + 1, 1);
            updRange(H + 1, H + 1, -1);
            updRange(A, A, 1);
            updRange(B - P + A + 1, B - P + A + 1, -1);
        }
    }

    ll ans = 0;
    FORU(i, 1, a.back().fi){
        ll tmp = query(i);
        ans += tmp * (tmp - 1) / 2;
    }
    cout << ans;
    return 0;
}

Compilation message

sails.cpp: In function 'void Fi()':
sails.cpp:20:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |         freopen(PROB".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sails.cpp:21:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |         freopen(PROB".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 1 ms 320 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 328 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 5 ms 1864 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 13 ms 844 KB Output is correct
2 Correct 44 ms 844 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 35 ms 1036 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 80 ms 1480 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 155 ms 2448 KB Output is correct
2 Correct 132 ms 3336 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 127 ms 2572 KB Output is correct
2 Correct 115 ms 3176 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 183 ms 2752 KB Output is correct
2 Correct 136 ms 2640 KB Output is correct