Submission #527691

# Submission time Handle Problem Language Result Execution time Memory
527691 2022-02-18T03:28:15 Z 79brue From Hacks to Snitches (BOI21_watchmen) C++14
0 / 100
99 ms 66808 KB
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const int LIM = 1600;

struct dat{
    int x, f, y;
    dat(){}
    dat(int x, int f, int y): x(x), f(f), y(y){}

    bool operator<(const dat &r)const{
        return y>r.y;
    }
};

int n, m, k;
vector<int> link[250002];
int cycleLen[250002];
int cycleIdx[250002];
vector<int> dist[250002];
vector<bool> visited[250002];

queue<dat> pq[1602];

void update(dat tmp){
    if(visited[tmp.x][tmp.f]) return;
    visited[tmp.x][tmp.f] = 1;
    dist[tmp.x][tmp.f] = tmp.y;
    pq[tmp.y%LIM].push(tmp);
}

int main(){
    scanf("%d %d", &n, &m);
    for(int i=1; i<=m; i++){
        int x, y;
        scanf("%d %d", &x, &y);
        link[x].push_back(y);
        link[y].push_back(x);
    }

    scanf("%d", &k);
    while(k--){
        int l;
        scanf("%d", &l);
        for(int j=0; j<l; j++){
            int tmp;
            scanf("%d", &tmp);
            cycleLen[tmp] = l;
            cycleIdx[tmp] = j;
        }
    }

    for(int i=1; i<=n; i++){
        if(!cycleLen[i]) cycleLen[i] = 1;
        dist[i] = vector<int> (cycleLen[i], 1e9);
        visited[i].resize(cycleLen[i]);
    }

    update(dat(1, 0, 0));
    for(int d=0; ; d+=LIM){
        bool exist = 0;
        for(int e=0; e<LIM; e++){
            while(!pq[e].empty()){
                exist=1;
                dat tmp = pq[d+e].front(); pq[d+e].pop();
                int x = tmp.x, f = tmp.f, y = tmp.y;
                assert(f < cycleLen[x]);

                if(x==n){
                    printf("%d", y);
                    return 0;
                }

                if(cycleLen[x] == 1){
                    for(int nxt: link[x]){
                        if(cycleLen[nxt] == 1) update(dat(nxt, 0, y+1));
                        else{
                            if(cycleIdx[nxt] != (y+1)%cycleLen[nxt]) update(dat(nxt, (y+1)%cycleLen[nxt], y+1));
                            int tn = (y+1-cycleIdx[nxt]-1+cycleLen[nxt]-1) / cycleLen[nxt] * cycleLen[nxt] + cycleIdx[nxt]+1;
                            update(dat(nxt, tn%cycleLen[nxt], tn));
                        }
                    }
                }
                else{
                    for(int nxt: link[x]){
                        if(cycleLen[nxt] == 1) update(dat(nxt, 0, y+1));
                        else{
                            int nf = (f+1)%cycleLen[nxt];
                            if(nf == cycleIdx[nxt]) continue;
                            if(nf == cycleIdx[x] && f%cycleLen[nxt] == cycleIdx[nxt]) continue;
                            update(dat(nxt, nf, y+1));
                        }
                    }
                }
            }
        }
        if(!exist) break;
    }

    printf("impossible");
}

Compilation message

watchmen.cpp: In function 'int main()':
watchmen.cpp:35:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
watchmen.cpp:38:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |         scanf("%d %d", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~
watchmen.cpp:43:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     scanf("%d", &k);
      |     ~~~~~^~~~~~~~~~
watchmen.cpp:46:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |         scanf("%d", &l);
      |         ~~~~~^~~~~~~~~~
watchmen.cpp:49:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |             scanf("%d", &tmp);
      |             ~~~~~^~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 30 ms 23884 KB Output is correct
2 Runtime error 99 ms 66732 KB Execution killed with signal 6
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 29 ms 23904 KB Output is correct
2 Runtime error 83 ms 66808 KB Execution killed with signal 6
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 29 ms 23904 KB Output is correct
2 Runtime error 83 ms 66808 KB Execution killed with signal 6
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 29 ms 23904 KB Output is correct
2 Runtime error 83 ms 66808 KB Execution killed with signal 6
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 30 ms 23884 KB Output is correct
2 Runtime error 99 ms 66732 KB Execution killed with signal 6
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 30 ms 23884 KB Output is correct
2 Runtime error 99 ms 66732 KB Execution killed with signal 6
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 30 ms 23884 KB Output is correct
2 Runtime error 99 ms 66732 KB Execution killed with signal 6
3 Halted 0 ms 0 KB -