Submission #450177

#	Time	Username	Problem	Language	Result	Execution time	Memory
450177		Mestu	Robot (JOI21_ho_t4)	C++14	100 / 100	605 ms	77876 KiB

Main

#include <bits/stdc++.h>
#define va first
#define vb second
using namespace std;
typedef long long lint;
typedef pair<int, int> pint;
typedef pair<lint, lint> plint;
const int MAX = 4e5 + 10;
 
int n, m;
lint D[MAX];
vector<int> A;
vector<plint> G[MAX];
vector<pair<int, pint>> V[MAX];
int main() {
    cin.tie(0); ios_base::sync_with_stdio(0);
    cin >> n >> m;
    for (int i = 0; i < m; i++) {
        int a, b, c, p; cin >> a >> b >> c >> p;
        V[a].push_back({ c, {p, b} });
        V[b].push_back({ c, {p, a} });
    }
    int sz = n;
    for (int i = 1; i < n; i++) {
        if (V[i].empty()) continue; sort(V[i].begin(), V[i].end());
        for (int l = 0, r = 0; l < V[i].size(); l = r) {
            lint s = 0;
            while (r < V[i].size() && V[i][l].va == V[i][r].va) s += V[i][r++].vb.va;
            if (r - l == 1) G[i].emplace_back(0, V[i][l].vb.vb);
            else {
                G[i].emplace_back(0, ++sz);
                for (int j = l; j < r; j++) {
                    pint x = V[i][j].vb;
                    G[i].emplace_back(x);
                    G[x.vb].emplace_back(0, sz);
                    G[sz].emplace_back(s - x.va, x.vb);
                }
            }
        }
    }
    priority_queue<plint> Q; Q.emplace(0, 1);
    for (int i = 1; i <= sz; i++) D[i] = 4e18;
    while (!Q.empty()) {
        auto t = Q.top(); Q.pop();
        if (D[t.vb] != 4e18) continue; D[t.vb] = -t.va;
        for (auto nxt : G[t.vb]) Q.emplace(t.va - nxt.va, nxt.vb);
    }
    cout << (D[n] == 4e18 ? -1 : D[n]);
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:25:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   25 |         if (V[i].empty()) continue; sort(V[i].begin(), V[i].end());
      |         ^~
Main.cpp:25:37: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   25 |         if (V[i].empty()) continue; sort(V[i].begin(), V[i].end());
      |                                     ^~~~
Main.cpp:26:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, std::pair<int, int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |         for (int l = 0, r = 0; l < V[i].size(); l = r) {
      |                                ~~^~~~~~~~~~~~~
Main.cpp:28:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, std::pair<int, int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |             while (r < V[i].size() && V[i][l].va == V[i][r].va) s += V[i][r++].vb.va;
      |                    ~~^~~~~~~~~~~~~
Main.cpp:45:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   45 |         if (D[t.vb] != 4e18) continue; D[t.vb] = -t.va;
      |         ^~
Main.cpp:45:40: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   45 |         if (D[t.vb] != 4e18) continue; D[t.vb] = -t.va;
      |                                        ^

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