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Submission #941279

# Submission time Handle Problem Language Result Execution time Memory
941279 2024-03-08T12:32:08 Z phoenix0423 Alternating Current (BOI18_alternating) C++17
32 / 100
 74 ms 14444 KB 
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pll;
#define fastio ios::sync_with_stdio(false), cin.tie(0)
#define pb push_back
#define eb emplace_back
#define f first
#define s second
#define int long long
#define lowbit(x) x&-x
const int maxn = 3e5 + 5;
const int INF = 1e18;
int n, m;

struct seg{
    int l, r, id;
    seg(){}
    seg(int _l, int _r, int _id) : l(_l), r(_r), id(_id){
        if(r < l) r += n;
    }
    bool operator < (const seg& other) const{
        if(l != other.l) return l < other.l;
        return r < other.r;
    }
};

class comp{
    public:
        bool operator ()(seg a, seg b){
            if(a.r != b.r) return a.r < b.r;
            else return a.l < b.l;
        }
};

int st[maxn * 4], tag[maxn * 4];

void cast(int val, int v){
    st[v] += val, tag[v] += val;
}

void push(int v){
    if(tag[v]){
        cast(tag[v], v * 2);
        cast(tag[v], v * 2 + 1);
        tag[v] = 0;
    }
}
void upd(int l, int r, int val, int v = 1, int L = 0, int R = n - 1){
    if(l > R || r < L) return;
    if(l <= L && r >= R){
        st[v] += val, tag[v] += val;
        return;
    }
    push(v);
    int m = (L + R) / 2;
    upd(l, r, val, v * 2, L, m);
    upd(l, r, val, v * 2 + 1, m + 1, R);
    st[v] = min(st[v * 2], st[v * 2 + 1]);
}
int qry(int l, int r, int v = 1, int L = 0, int R = n - 1){
    if(l > R || r < L) return INF;
    if(l <= L && r >= R) return st[v];
    push(v);
    int m = (L + R) / 2;
    return min(qry(l, r, v * 2, L, m), qry(l, r, v * 2 + 1, m + 1, R));
}
void insert(int l, int r, int val){
    r %= n;
    if(l <= r) upd(l, r, val);
    else upd(l, n - 1, val), upd(0, r, val);
}

bool ck(seg a){
    a.r %= n;
    if(a.l <= a.r) return qry(a.l, a.r) >= 2;
    else return min(qry(a.l, n - 1), qry(0, a.r)) >= 2;
}
signed main(void){
    fastio;
    cin>>n>>m;
    vector<seg> e;
    for(int i = 0; i < m; i++){
        int a, b;
        cin>>a>>b;
        a--, b--;
        insert(a, b, 1);
        e.pb(seg(a, b, i));
    }
    if(qry(0, n - 1) < 2){
        cout<<"impossible\n";
        return 0;
    }
    sort(e.begin(), e.end());
    int st = e[0].l, r = e[0].l - 1;
    vector<int> ans(m);
    int id = 0;
    priority_queue<seg, vector<seg>, comp> q;
    int dist = 0;
    while(true){
        // cout<<"r : "<<r<<"\n";
        while(id < m && e[id].l <= r + 1){
            // cout<<"push : "<<e[id].l<<" "<<e[id].r<<" "<<e[id].id<<"\n";
            q.push(e[id]);
            id++;
        }
        while(true){
            if(q.empty()){
                cout<<"impossible\n";
                return 0;
            }
            seg cur = q.top(); q.pop();
            if(!ck(cur)) continue;
            if(cur.r <= r) continue;
            // cout<<"use : "<<cur.l<<" "<<cur.r<<" "<<cur.id<<"\n";
            insert(cur.l, cur.r, -1);
            ans[cur.id] = 1;
            dist += cur.r - r;
            r = cur.r;
            break;
        }
        // cout<<dist<<"\n";
        if(dist >= n) break;
    }
    for(auto x : ans) cout<<x;
    cout<<"\n";
}

Compilation message

alternating.cpp: In function 'int main()':
alternating.cpp:95:9: warning: unused variable 'st' [-Wunused-variable]
   95 |     int st = e[0].l, r = e[0].l - 1;
      |         ^~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 1 ms 2396 KB Output is correct
4 Correct 1 ms 2396 KB Output is correct
5 Correct 0 ms 2396 KB Output is correct
6 Correct 1 ms 2396 KB Output is correct
7 Correct 1 ms 2648 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2396 KB Output is correct
10 Correct 1 ms 2396 KB Output is correct
11 Correct 1 ms 2396 KB Output is correct
12 Correct 1 ms 2396 KB Output is correct
13 Correct 1 ms 2396 KB Output is correct
14 Correct 1 ms 2512 KB Output is correct
15 Correct 1 ms 2396 KB Output is correct
16 Correct 1 ms 2396 KB Output is correct
17 Correct 1 ms 2396 KB Output is correct
18 Correct 1 ms 2392 KB Output is correct
19 Correct 1 ms 2396 KB Output is correct
20 Correct 1 ms 2396 KB Output is correct
21 Correct 1 ms 2396 KB Output is correct
22 Correct 1 ms 2396 KB Output is correct
23 Correct 1 ms 2516 KB Output is correct
24 Correct 1 ms 2396 KB Output is correct
25 Correct 1 ms 2396 KB Output is correct
26 Correct 1 ms 2396 KB Output is correct
27 Correct 1 ms 2396 KB Output is correct
28 Correct 1 ms 2392 KB Output is correct
29 Correct 1 ms 2396 KB Output is correct
30 Correct 1 ms 2392 KB Output is correct
31 Correct 1 ms 2396 KB Output is correct
32 Correct 2 ms 2396 KB Output is correct
33 Correct 1 ms 2648 KB Output is correct
34 Correct 1 ms 2396 KB Output is correct
35 Correct 1 ms 2392 KB Output is correct
36 Correct 1 ms 2392 KB Output is correct
37 Correct 1 ms 2392 KB Output is correct
38 Correct 1 ms 2396 KB Output is correct
39 Correct 1 ms 2396 KB Output is correct
40 Correct 1 ms 2396 KB Output is correct

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 1 ms 2396 KB Output is correct
4 Correct 1 ms 2396 KB Output is correct
5 Correct 0 ms 2396 KB Output is correct
6 Correct 1 ms 2396 KB Output is correct
7 Correct 1 ms 2648 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2396 KB Output is correct
10 Correct 1 ms 2396 KB Output is correct
11 Correct 1 ms 2396 KB Output is correct
12 Correct 1 ms 2396 KB Output is correct
13 Correct 1 ms 2396 KB Output is correct
14 Correct 1 ms 2512 KB Output is correct
15 Correct 1 ms 2396 KB Output is correct
16 Correct 1 ms 2396 KB Output is correct
17 Correct 1 ms 2396 KB Output is correct
18 Correct 1 ms 2392 KB Output is correct
19 Correct 1 ms 2396 KB Output is correct
20 Correct 1 ms 2396 KB Output is correct
21 Correct 1 ms 2396 KB Output is correct
22 Correct 1 ms 2396 KB Output is correct
23 Correct 1 ms 2516 KB Output is correct
24 Correct 1 ms 2396 KB Output is correct
25 Correct 1 ms 2396 KB Output is correct
26 Correct 1 ms 2396 KB Output is correct
27 Correct 1 ms 2396 KB Output is correct
28 Correct 1 ms 2392 KB Output is correct
29 Correct 1 ms 2396 KB Output is correct
30 Correct 1 ms 2392 KB Output is correct
31 Correct 1 ms 2396 KB Output is correct
32 Correct 2 ms 2396 KB Output is correct
33 Correct 1 ms 2648 KB Output is correct
34 Correct 1 ms 2396 KB Output is correct
35 Correct 1 ms 2392 KB Output is correct
36 Correct 1 ms 2392 KB Output is correct
37 Correct 1 ms 2392 KB Output is correct
38 Correct 1 ms 2396 KB Output is correct
39 Correct 1 ms 2396 KB Output is correct
40 Correct 1 ms 2396 KB Output is correct
41 Correct 1 ms 2392 KB Output is correct
42 Incorrect 1 ms 2396 KB 'impossible' claimed, but there is a solution
43 Halted 0 ms 0 KB -

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 1 ms 2396 KB Output is correct
4 Correct 1 ms 2396 KB Output is correct
5 Correct 0 ms 2396 KB Output is correct
6 Correct 1 ms 2396 KB Output is correct
7 Correct 1 ms 2648 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2396 KB Output is correct
10 Correct 1 ms 2396 KB Output is correct
11 Correct 1 ms 2396 KB Output is correct
12 Correct 1 ms 2396 KB Output is correct
13 Correct 1 ms 2396 KB Output is correct
14 Correct 1 ms 2512 KB Output is correct
15 Correct 1 ms 2396 KB Output is correct
16 Correct 1 ms 2396 KB Output is correct
17 Correct 1 ms 2396 KB Output is correct
18 Correct 1 ms 2392 KB Output is correct
19 Correct 1 ms 2396 KB Output is correct
20 Correct 1 ms 2396 KB Output is correct
21 Correct 1 ms 2396 KB Output is correct
22 Correct 1 ms 2396 KB Output is correct
23 Correct 1 ms 2516 KB Output is correct
24 Correct 1 ms 2396 KB Output is correct
25 Correct 1 ms 2396 KB Output is correct
26 Correct 1 ms 2396 KB Output is correct
27 Correct 1 ms 2396 KB Output is correct
28 Correct 1 ms 2392 KB Output is correct
29 Correct 1 ms 2396 KB Output is correct
30 Correct 1 ms 2392 KB Output is correct
31 Correct 1 ms 2396 KB Output is correct
32 Correct 2 ms 2396 KB Output is correct
33 Correct 1 ms 2648 KB Output is correct
34 Correct 1 ms 2396 KB Output is correct
35 Correct 1 ms 2392 KB Output is correct
36 Correct 1 ms 2392 KB Output is correct
37 Correct 1 ms 2392 KB Output is correct
38 Correct 1 ms 2396 KB Output is correct
39 Correct 1 ms 2396 KB Output is correct
40 Correct 1 ms 2396 KB Output is correct
41 Correct 1 ms 2392 KB Output is correct
42 Incorrect 1 ms 2396 KB 'impossible' claimed, but there is a solution
43 Halted 0 ms 0 KB -

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 10956 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 24 ms 8396 KB Output is correct
4 Correct 26 ms 8404 KB Output is correct
5 Correct 63 ms 12476 KB Output is correct
6 Correct 43 ms 10792 KB Output is correct
7 Correct 56 ms 13984 KB Output is correct
8 Correct 4 ms 6748 KB Output is correct
9 Correct 3 ms 6492 KB Output is correct
10 Correct 74 ms 12528 KB Output is correct
11 Correct 48 ms 11552 KB Output is correct
12 Correct 44 ms 9680 KB Output is correct
13 Correct 1 ms 4444 KB Output is correct
14 Correct 1 ms 4700 KB Output is correct
15 Correct 49 ms 10632 KB Output is correct
16 Correct 23 ms 7688 KB Output is correct
17 Correct 73 ms 14444 KB Output is correct
18 Correct 55 ms 10980 KB Output is correct
19 Correct 5 ms 6748 KB Output is correct
20 Correct 60 ms 9268 KB Output is correct

Subtask #5
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2396 KB Output is correct
3 Correct 1 ms 2396 KB Output is correct
4 Correct 1 ms 2396 KB Output is correct
5 Correct 0 ms 2396 KB Output is correct
6 Correct 1 ms 2396 KB Output is correct
7 Correct 1 ms 2648 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2396 KB Output is correct
10 Correct 1 ms 2396 KB Output is correct
11 Correct 1 ms 2396 KB Output is correct
12 Correct 1 ms 2396 KB Output is correct
13 Correct 1 ms 2396 KB Output is correct
14 Correct 1 ms 2512 KB Output is correct
15 Correct 1 ms 2396 KB Output is correct
16 Correct 1 ms 2396 KB Output is correct
17 Correct 1 ms 2396 KB Output is correct
18 Correct 1 ms 2392 KB Output is correct
19 Correct 1 ms 2396 KB Output is correct
20 Correct 1 ms 2396 KB Output is correct
21 Correct 1 ms 2396 KB Output is correct
22 Correct 1 ms 2396 KB Output is correct
23 Correct 1 ms 2516 KB Output is correct
24 Correct 1 ms 2396 KB Output is correct
25 Correct 1 ms 2396 KB Output is correct
26 Correct 1 ms 2396 KB Output is correct
27 Correct 1 ms 2396 KB Output is correct
28 Correct 1 ms 2392 KB Output is correct
29 Correct 1 ms 2396 KB Output is correct
30 Correct 1 ms 2392 KB Output is correct
31 Correct 1 ms 2396 KB Output is correct
32 Correct 2 ms 2396 KB Output is correct
33 Correct 1 ms 2648 KB Output is correct
34 Correct 1 ms 2396 KB Output is correct
35 Correct 1 ms 2392 KB Output is correct
36 Correct 1 ms 2392 KB Output is correct
37 Correct 1 ms 2392 KB Output is correct
38 Correct 1 ms 2396 KB Output is correct
39 Correct 1 ms 2396 KB Output is correct
40 Correct 1 ms 2396 KB Output is correct
41 Correct 1 ms 2392 KB Output is correct
42 Incorrect 1 ms 2396 KB 'impossible' claimed, but there is a solution
43 Halted 0 ms 0 KB -