/*
https://github.com/mostafa-saad/MyCompetitiveProgramming/blob/master/Olympiad/COCI/official/2017/contest1_solutions/solutions.pdf
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define For(i, a, b) for(int i=a; i<b; i++)
#define ffi For(i, 0, N)
#define ffj For(j, 0, M)
#define ffa ffi ffj
#define s <<" "<<
#define c <<" : "<<
#define w cout
#define e endl//"\n"
#define pb push_back
#define mp make_pair
#define a first
#define b second
//#define int ll
const int MAXN=1000000, INF=1000000000;
///500,000,000
int N, val[MAXN], sm = INF, dp[MAXN], o1, o2, dp1[MAXN], n1[MAXN], dp2[MAXN];
vector<int> adj[MAXN];
void go (int at, int par) {
int b1=0, b2=0;
if (val[at] == 1) dp[at] = 1;
for (int i: adj[at]) if (i != par) {
go(i, at);
if (val[at] == 1) dp[at] = max(dp[at], 1+dp[i]);
if (dp[i] > b2) {
b2 = dp[i];
if (b2 > b1) swap(b1, b2);
}
}
if (val[at] == 1) o1 = max(o1, b1+b2+1);
}
void go2(int at, int par) {
for (int i: adj[at]) if (i != par) {
if (dp[i] > dp1[at]) {
dp2[at] = dp1[at];
dp1[at] = dp[i];
n1[at] = i;
}
else if (dp[i] > dp2[at]) dp2[at] = dp[i];
}
if (par != -1) {
int x;
if (n1[par] == at) x = dp2[par];
else x = dp1[par];
if (x > dp1[at]) {
dp2[at] = dp1[at];
dp1[at] = x;
n1[at] = par;
}
else if (x > dp2[at]) dp2[at] = x;
}
if (val[at] == 1) {dp1[at]++; dp2[at]++;}
if (val[at] == 2) o2 = max(o2, dp2[at]);
for (int i: adj[at]) if (i != par) go2(i, at);
}
main() {
//ifstream cin("test.in");
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> N;
For (i, 1, N) {int a, b; cin >> a >> b; a--; b--; adj[a].pb(b); adj[b].pb(a);}
ffi {n1[i] = -1; cin >> val[i]; sm = min(sm, val[i]);}
if (sm != 1) {
w<< sm <<"/1"<<e;
return 0;
}
go(0, -1);
go2(0,-1);
if (o2 == o1) w<< "2/" << 2*o2+1<<e;
else w<< "1/" << o1<<e;
}
Compilation message
mag.cpp:63:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
main() {
^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
22 ms |
24056 KB |
Output is correct |
2 |
Incorrect |
23 ms |
23928 KB |
Output isn't correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
24 ms |
24056 KB |
Output is correct |
2 |
Incorrect |
23 ms |
23928 KB |
Output isn't correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
394 ms |
109824 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
19 ms |
23800 KB |
Output is correct |
2 |
Incorrect |
526 ms |
167388 KB |
Output isn't correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
512 ms |
166772 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
419 ms |
89800 KB |
Output is correct |
2 |
Incorrect |
314 ms |
72440 KB |
Output isn't correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
406 ms |
92896 KB |
Output is correct |
2 |
Correct |
80 ms |
30584 KB |
Output is correct |
3 |
Correct |
476 ms |
170372 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
79 ms |
30576 KB |
Output is correct |
2 |
Correct |
425 ms |
90360 KB |
Output is correct |
3 |
Correct |
349 ms |
57668 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
376 ms |
87152 KB |
Output is correct |
2 |
Correct |
390 ms |
90836 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
446 ms |
90568 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |