oj.uz

Submission #651176

# Submission time Handle Problem Language Result Execution time Memory
651176 2022-10-17T15:02:22 Z Wunka Stove (JOI18_stove) C++17
100 / 100
 60 ms 4560 KB 
#include<bits/stdc++.h>
using namespace std;

#define ll long long 
#define fi first 
#define se second 

const int INF = 1e9; 

class DSU {
public:
    vector<int> sz; 
    vector<int> id; 
    int components = 0; 
    
    void init(int n) {
        sz.assign(n, 1); 
        id.assign(n, 0); 
        for(int i = 0; i < n; i++) {
            id[i] = i; 
        }
        components = n; 
    }

    int find(int x) {
        if(x == id[x]) return x; 
        return (id[x] = find(id[x])); 
    }

    void unite(int x, int y) {
        x = find(x); 
        y = find(y); 
        if(x == y) return; 

        if(sz[x] < sz[y]) 
            swap(x, y); 
        id[y] = x; 
        sz[x] += sz[y]; 
        components--;  
    }

    int getComponents() { return components; }  
}; 

struct edge {
    int x, y, w; 
};

bool cmp(const edge& a, const edge& b) {
    return (a.w <= b.w); 
}


int main() {
    int n, k; 
    cin >> n >> k; 

    vector<ll> t(n); 
    for(int i = 0; i < n; i++) cin >> t[i]; 
    sort(t.begin(), t.end()); 
    if(n == k) {
        cout << n << '\n'; 
        return 0;  
    }

    // get our edges 
    vector<edge> e;
    for(int i = 0; i < n - 1; i++) {
        edge a; 
        a.x = i; 
        a.y = i + 1; 
        a.w = (t[i + 1] - t[i]); 
        e.push_back(a); 
    }


    // sort them 
    sort(e.begin(), e.end(), cmp); 
    /*
    cout << "my edges: " << '\n'; 
    for(int i = 0; i < n - 1; i++) {
        cout << e[i].x << ' ' << e[i].y << ' ' << e[i].w << '\n'; 
    }
    */

    // unify them into components 
    DSU uf;
    uf.init(n); 
    
   for(int i = 0; i < (n - 1) - (k - 1); i++) {
        //cout << "trying to unite " << e[i].x << ' ' << e[i].y << '\n';  
        uf.unite(e[i].x, e[i].y);
        //cout << "PASSED THIS CASE!" << '\n'; 
    }
   

    // for future 
    int m = uf.getComponents(); // number of components; 
    vector<pair<ll, ll>> intervals(n); 
    for(int i = 0; i < n; i++) {
        intervals[i].fi = INF;  
        intervals[i].se = -INF;  
    }

    for(int i = 0; i < n; i++) {
        int root = uf.find(i); 
        intervals[root].fi = min(intervals[root].fi, t[i]);  
        intervals[root].se = max(intervals[root].se, t[i] + 1);  
    }

    // calculate the answer
    ll ans = 0;
    /*
    for(int i = 0; i < n; i++) {
        cout << intervals[i].fi << ' ' << intervals[i].se << '\n'; 
    } 
    */ 
    for(int i = 0; i < n; i++) {
        if(intervals[i].fi != INF) {
            ans += intervals[i].se - intervals[i].fi; 
        }
    }

    cout << ans << '\n'; 
}

Compilation message

stove.cpp: In function 'int main()':
stove.cpp:98:9: warning: unused variable 'm' [-Wunused-variable]
   98 |     int m = uf.getComponents(); // number of components;
      |         ^

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 2 ms 340 KB Output is correct
11 Correct 2 ms 340 KB Output is correct
12 Correct 2 ms 340 KB Output is correct
13 Correct 2 ms 340 KB Output is correct
14 Correct 2 ms 340 KB Output is correct
15 Correct 2 ms 340 KB Output is correct

Subtask #3
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 2 ms 340 KB Output is correct
11 Correct 2 ms 340 KB Output is correct
12 Correct 2 ms 340 KB Output is correct
13 Correct 2 ms 340 KB Output is correct
14 Correct 2 ms 340 KB Output is correct
15 Correct 2 ms 340 KB Output is correct
16 Correct 57 ms 4556 KB Output is correct
17 Correct 60 ms 4516 KB Output is correct
18 Correct 56 ms 4532 KB Output is correct
19 Correct 59 ms 4532 KB Output is correct
20 Correct 57 ms 4552 KB Output is correct
21 Correct 56 ms 4532 KB Output is correct
22 Correct 53 ms 4528 KB Output is correct
23 Correct 53 ms 4560 KB Output is correct
24 Correct 55 ms 4540 KB Output is correct