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Submission #895768

# Submission time Handle Problem Language Result Execution time Memory
895768 2023-12-30T19:03:37 Z abcvuitunggio Flood (IOI07_flood) C++17
100 / 100
 141 ms 29664 KB 
#include <bits/stdc++.h>
using namespace std;
int n,w,x[100001],y[100001],a[200001],b[200001],dx[4]={1,0,-1,0},dy[4]={0,1,0,-1},p[400001],l[100001],mx[100001];
vector <int> safe,nxt[100001][4];
vector <pair <int, int>> q[100005];
int f(int i){
    return (l[i]==i?i:l[i]=f(l[i]));
}
int main(){
    ios_base::sync_with_stdio(NULL);cin.tie(nullptr);
    cin >> n;
    iota(l,l+n+1,0);
    for (int i=1;i<=n;i++)
        cin >> x[i] >> y[i];
    cin >> w;
    for (int i=1;i<=w;i++){
        cin >> a[i] >> b[i];
        l[f(a[i])]=f(b[i]);
        for (int j=0;j<4;j++)
            if (abs(dx[j])+abs(x[a[i]]+dx[j]-x[b[i]])==abs(x[a[i]]-x[b[i]])&&abs(dy[j])+abs(y[a[i]]+dy[j]-y[b[i]])==abs(y[a[i]]-y[b[i]])){
                nxt[a[i]][j]={i};
                nxt[b[i]][(j+2)%4]={i+w};
                break;
            }
    }
    for (int i=1;i<=n;i++){
        int j=f(i);
        if (!mx[j]||x[mx[j]]>x[i]||(x[mx[j]]==x[i]&&y[mx[j]]<y[i]))
            mx[j]=i;
    }
    for (int i=1;i<=n;i++)
        if (i==f(i))
            for (int j=0;j<4;j++)
                if (!nxt[mx[i]][(j+3)%4].empty()){
                    q[1].push_back({nxt[mx[i]][(j+3)%4][0],(j+3)%4});
                    break;
                }
    for (int i=1;i<n+5;i++)
        while (!q[i].empty()){
            auto [u,d]=q[i].back();
            q[i].pop_back();
            if (p[u])
                continue;
            p[u]=i;
            q[i+1].push_back({(u>w?u-w:u+w),(d+2)%4});
            int cur=(u>w?a[u-w]:b[u]);
            for (int j=0;j<4;j++)
                if (!nxt[cur][(d+j+3)%4].empty()){
                    int v=nxt[cur][(d+j+3)%4][0];
                    nxt[cur][(d+j+3)%4].clear();
                    q[i].push_back({v,(d+j+3)%4});
                    break;
                }
        }
    for (int i=1;i<=w;i++)
        if (p[i]==p[i+w])
            safe.push_back(i);
    cout << safe.size() << '\n';
    for (int i:safe)
        cout << i << '\n';
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14936 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14940 KB Output is correct
2 Correct 3 ms 14940 KB Output is correct
3 Correct 3 ms 14940 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14940 KB Output is correct

Subtask #4
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 15192 KB Output is correct
2 Correct 3 ms 14936 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14940 KB Output is correct
2 Correct 3 ms 14940 KB Output is correct

Subtask #6
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14940 KB Output is correct

Subtask #7
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14940 KB Output is correct

Subtask #8
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 14940 KB Output is correct
2 Correct 3 ms 15028 KB Output is correct

Subtask #9
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 15092 KB Output is correct
2 Correct 3 ms 14940 KB Output is correct

Subtask #10
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 17112 KB Output is correct

Subtask #11
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 47 ms 23164 KB Output is correct

Subtask #12
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 46 ms 24068 KB Output is correct
2 Correct 141 ms 28568 KB Output is correct

Subtask #13
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 117 ms 26704 KB Output is correct
2 Correct 117 ms 29664 KB Output is correct

Subtask #14
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 113 ms 28524 KB Output is correct
2 Correct 96 ms 25500 KB Output is correct