Submission #1224622

#	Time	Username	Problem	Language	Result	Execution time	Memory
1224622		sokratisi	From Hacks to Snitches (BOI21_watchmen)	C++20	Compilation error	0 ms	0 KiB

watchmen

#include <bits/stdc++.h>

using namespace std;

int n, m, k, a, b, l;
vector<int> adj[100010];
int cl[130], dst[100010][130];
bool vis[100010][130];

int main() {
    scanf("%d%d", &n, &m);
    for (int i = 0; i < m; i++) {
        scanf("%d%d", &a, &b);
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    scanf("%d%d", &k, &l);
    for (int i = 0; i < l; i++) scanf("%d", &cl[i]);
    cl[l] = cl[0];

    for (int i = 1; i <= n; i++) {
        for (int j = 0; j < l; j++) {
            dst[i][j] = -1;
        }
    }
    
    dst[1][0] = 0;
    queue<pair<int, int>> q;
    q.push({1, 0});
    // careful with staying still
    while (!q.empty()) {
        int node = q.front().first, tm = q.front().second;
        q.pop();
        if (vis[node][tm]) continue;
        vis[node][tm] = true;
        if (!vis[node][(tm+1)%l] && cl[tm+1] != node) {
            q.push({node, (tm+1)%l});
            dst[node][(tm+1)%l] = dst[node][tm] + 1;
        }
        for (auto u: adj[node]) {
            if (!vis[u][tm+1] && /*fill in*/) {
                q.push({u, (tm+1)%l});
                dst[u][(tm+1)%l] = dst[node][tm] + 1;                
            }
        }
    }
    if (dst[n][0] == INT_MAX) printf("impossible\n");
    else {
        int ans = INT_MAX;
        for (int j = 0; j < l; j++) ans = min(ans, dst[n][j]);
        printf("%d\n", ans);
    }
    

    return 0;
}

Compilation message (stderr)

watchmen.cpp: In function 'int main()':
watchmen.cpp:41:45: error: expected primary-expression before ')' token
   41 |             if (!vis[u][tm+1] && /*fill in*/) {
      |                                             ^
watchmen.cpp:11:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
watchmen.cpp:13:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |         scanf("%d%d", &a, &b);
      |         ~~~~~^~~~~~~~~~~~~~~~
watchmen.cpp:17:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |     scanf("%d%d", &k, &l);
      |     ~~~~~^~~~~~~~~~~~~~~~
watchmen.cpp:18:38: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |     for (int i = 0; i < l; i++) scanf("%d", &cl[i]);
      |                                 ~~~~~^~~~~~~~~~~~~~