Submission #1254042

#	Time	Username	Problem	Language	Result	Execution time	Memory
1254042		badge881	Robot (JOI21_ho_t4)	C++20	100 / 100	86 ms	15344 KiB

Main

#include <bits/stdc++.h>
#define ll long long
using namespace std;

const int N = 1e5 + 5;
const int M = 2e5 + 5;
const ll INF = 1e18;

struct Edge
{
    int a, b, c;
};

int n, m;
vector<Edge> adj[N];
ll dp[N], col[M], sum[M];
bool vis[N];

int main()
{
    scanf("%d %d", &n, &m);
    for (int x = 0; x < m; x++)
    {
        int a, b, c, p;
        scanf("%d %d %d %d", &a, &b, &c, &p);
        adj[a].push_back({b, c, p});
        adj[b].push_back({a, c, p});
    }
    for (int x = 1; x <= n; x++)
    {
        dp[x] = INF;
        vis[x] = 0;
    }
    priority_queue<pair<ll, int>> pq;
    pq.push({0, 1});
    dp[1] = 0;
    while (!pq.empty())
    {
        int i = pq.top().second;
        pq.pop();
        if (vis[i])
            continue;
        vis[i] = true;
        for (Edge &a : adj[i])
        {
            sum[a.b] = 0;
            col[a.b] = INF;
        }
        for (Edge &a : adj[i])
        {
            sum[a.b] += a.c;
            col[a.b] = min(col[a.b], dp[a.a]);
        }
        for (Edge &a : adj[i])
        {
            ll val = min({dp[i] + a.c, dp[i] + sum[a.b] - a.c, sum[a.b] + col[a.b] - a.c});
            int j = a.a;
            if (val < dp[j])
            {
                dp[j] = val;
                pq.push({-dp[j], j});
            }
        }
    }
    if (dp[n] == INF)
        printf("-1\n");
    else
        printf("%lld\n", dp[n]);
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:21:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
Main.cpp:25:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |         scanf("%d %d %d %d", &a, &b, &c, &p);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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