MELE3 - MELE3
Tác giả: khuc_tuan
Ngôn ngữ: C++
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
vector<int> ke[50050];
int n, m;
int F[50050];
int main() {
scanf("%d%d", &n, &m);
for(int i=0;i<m;++i) {
int u, v;
scanf("%d%d", &u, &v);
ke[u].push_back(v);
ke[v].push_back(u);
}
queue<int> q;
memset( F, 0x1f, sizeof(F));
F[1] = 0;
q.push(1);
while(!q.empty()) {
int u = q.front();
int t = F[u];
q.pop();
for(int k=0;k<ke[u].size();++k) {
int v = ke[u][k];
int len = u - v;
if(len < 0) len = -len;
if(u < v) {
int z = t;
if(z % (2*len) != 0)
z = (z / (2*len) + 1) * 2 * len;
if(F[v] > z + len) {
F[v] = z + len;
q.push(v);
}
}
else {
int z = t;
if(z % (2*len) != len) {
if(z % (2*len) < len) {
z = z / (2*len) * (2*len) + len;
}
else {
z = (z / (2*len) + 1) * (2*len) + len;
}
}
if(F[v] > z + len) {
F[v] = z + len;
q.push(v);
}
}
}
}
cout << F[n] * 5 << endl;
// system("pause");
return 0;
}