Submission #1274031

#	Time	Username	Problem	Language	Result	Execution time	Memory
1274031		wedonttalkanymore	Robot (JOI21_ho_t4)	C++20	100 / 100	923 ms	113992 KiB

Main

#include <bits/stdc++.h>
/*
    Brute to win
*/
using namespace std;
using ll = long long;

#define int long long
#define pii pair<ll, ll>
#define fi first
#define se second

const ll N = 2e5 + 5, inf = 1e18;

int n, m;
vector<pii> adj[N];
int c[N], p[N];
int dp1[N];      
map<int,int> dp2[N], pfs[N];
map<int, vector<pii>> adj1[N];  

struct item {
    int val, u, type;
    bool operator<(const item &o) const {
        return val > o.val;
    }
};

void dijk() {
    for (int i = 1; i <= n; i++) dp1[i] = inf;
    for (int i = 1; i <= n; i++) {
        for (auto [v,id] : adj[i]) {
            dp2[i][c[id]] = inf;
        }
    }
    dp1[1] = 0;
    priority_queue <item> q;
    q.push({0,1,0});

    while(!q.empty()) {
        auto [val,u,type] = q.top(); q.pop();
        if (type == 0) {
            if (val > dp1[u]) continue;
            for (auto [v,id] : adj[u]) {
                if (dp1[v] > dp1[u] + p[id]) {
                    dp1[v] = dp1[u] + p[id];
                    q.push({dp1[v], v, 0});
                }
                if (dp1[v] > dp1[u] + pfs[u][c[id]] - p[id]) {
                    dp1[v] = dp1[u] + pfs[u][c[id]] - p[id];
                    q.push({dp1[v], v, 0});
                }
                if (dp2[v][c[id]] > dp1[u]) {
                    dp2[v][c[id]] = dp1[u];
                    q.push({dp2[v][c[id]], v, c[id]});
                }
            }
        } else {
            if (val > dp2[u][type]) continue;
            for (auto [v,id] : adj1[u][type]) {
                if (dp1[v] > dp2[u][type] + pfs[u][type] - p[id]) {
                    dp1[v] = dp2[u][type] + pfs[u][type] - p[id];
                    q.push({dp1[v], v, 0});
                }
            }
        }
    }
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    if (fopen(".inp", "r")) {
        freopen(".inp", "r", stdin);
        freopen(".out", "w", stdout);
    }
    cin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int u,v; cin >> u >> v >> c[i] >> p[i];
        adj[u].emplace_back(v,i);
        adj[v].emplace_back(u,i);
        adj1[u][c[i]].emplace_back(v,i);
        adj1[v][c[i]].emplace_back(u,i);
        pfs[u][c[i]] += p[i];
        pfs[v][c[i]] += p[i];
    }
    dijk();
    cout << (dp1[n] >= inf ? -1 : dp1[n]);
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:74:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |         freopen(".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~
Main.cpp:75:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |         freopen(".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 34 / 34
• Subtask 2: 24 / 24
• Subtask 3: 42 / 42