Submission #30121

#	Time	Username	Problem	Language	Result	Execution time	Memory
30121		cdemirer	007 (CEOI14_007)	C++14	76.67 / 100	1000 ms	25796 KiB

007

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> llp;
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<vii> vvii;
#define mp(x, y) make_pair(x, y)
#define pb(x) push_back(x)

int N, M;
int Z, D, SV1, SV2;
vvi edges;
int sv1dists[200000], sv2dists[200000];

void dijsktra(int *dists, int s) {
	set<ii> S;
	for (int i = 0; i < N; i++) {
		if (i == s) {
			dists[i] = 0;
			S.insert(mp(dists[i], i));
			continue;
		}
		dists[i] = (int)1e9;
		S.insert(mp(dists[i], i));
	}
	while ( ! S.empty() ) {
		ii x = *S.begin();
		S.erase(S.begin());
		for (int i = 0; i < edges[x.second].size(); i++) {
			if (dists[x.second] + 1 < dists[edges[x.second][i]]) {
				S.erase(mp(dists[edges[x.second][i]], edges[x.second][i]));
				dists[edges[x.second][i]] = dists[x.second] + 1;
				S.insert(mp(dists[edges[x.second][i]], edges[x.second][i]));
			}
		}
	}
}

int moveit(int x) {
	int cnt = 0;
	while (true) {
		bool fnd = false;
		for (int i = 0; i < edges[x].size(); i++) {
			int v = edges[x][i];
			if (sv1dists[v] == sv1dists[x]-1 && sv1dists[v] == sv2dists[v]) {
				fnd = true;
				x = v;
				break;
			}
		}
		if (!fnd) return cnt;
		else cnt++;
	}
}

int main(int argc, char **argv) {

	//freopen("input", "r", stdin);
	//freopen("output", "w", stdout);

	scanf("%d%d", &N, &M);
	scanf("%d%d%d%d", &Z, &D, &SV1, &SV2);
	Z--; D--; SV1--; SV2--;
	edges.resize(N);
	for (int i = 0; i < M; i++) {
		int a, b; scanf("%d%d", &a, &b);
		a--, b--;
		edges[a].pb(b);
		edges[b].pb(a);
	}
	dijsktra(sv1dists, SV1);
	dijsktra(sv2dists, SV2);

	int ans = -1;
	ans = max(ans, min(sv1dists[D] - sv1dists[Z], sv2dists[D] - sv2dists[Z]));

	if (ans != -1 && sv1dists[D] == sv2dists[D] && sv1dists[Z] == sv2dists[Z]) {
		int a = moveit(D);
		int b = moveit(Z);
		if (a > b + ans) ans--;
	}
	printf("%d\n", ans);

	return 0;
}

Compilation message (stderr)

007.cpp: In function 'void dijsktra(int*, int)':
007.cpp:32:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < edges[x.second].size(); i++) {
                     ^
007.cpp: In function 'int moveit(int)':
007.cpp:46:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < edges[x].size(); i++) {
                     ^
007.cpp: In function 'int main(int, char**)':
007.cpp:64:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &N, &M);
                       ^
007.cpp:65:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d%d", &Z, &D, &SV1, &SV2);
                                       ^
007.cpp:69:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int a, b; scanf("%d%d", &a, &b);
                                  ^

• Subtask 1: 30 / 30
• Subtask 2: 46.666667 / 70