60 lines
1.4 KiB
C++
60 lines
1.4 KiB
C++
#include <iostream>
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#include <cstring>
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using namespace std;
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const int MAXN = 10005;
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vector<int> graph[MAXN];
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bool visited[MAXN];
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int dis_odd[MAXN], dis_even[MAXN];
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void find_shortest_path() {
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memset(dis_even, 0x3f, sizeof dis_even);
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memset(dis_odd, 0x3f, sizeof dis_odd);
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queue<pair<int, int>> q;
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for (int &i: graph[1]) {
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dis_odd[i] = 1;
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q.emplace(i, 1);
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}
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while (!q.empty()) {
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int x = q.front().first, y = q.front().second;
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for (int &i: graph[x]) {
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if (y % 2 == 0) {
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if (y + 1 < dis_odd[i]) {
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dis_odd[i] = y + 1;
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q.emplace(i, y + 1);
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}
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} else {
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if (y + 1 < dis_even[i]) {
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dis_even[i] = y + 1;
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q.emplace(i, y + 1);
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}
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}
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}
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q.pop();
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}
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}
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int main() {
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int n, m, q;
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cin >> n >> m >> q;
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for (int i = 0; i < m; i++) {
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int u, v;
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cin >> u >> v;
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graph[u].push_back(v);
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graph[v].push_back(u);
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}
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find_shortest_path();
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while (q--) {
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int u, v;
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cin >> u >> v;
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if (v % 2 == 0) {
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if (dis_even[u] > v) cout << "No" << endl;
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else cout << "Yes" << endl;
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} else {
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if (dis_odd[u] > v) cout << "No" << endl;
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else cout << "Yes" << endl;
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}
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}
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} |