#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
using ll = long long;
#define forn(i, n) for(int i=0; i<(int)n; ++i)
#define PB push_back
const int MAXN=100010, INF=100000000;
int n, x, y, res[MAXN][2][2];
bool vis[MAXN], gcov, gblue;
vector<int> g[MAXN];
inline int wrap(int v, bool blue, bool cover){
if(v!=y) return res[v][blue][cover];
else if((gcov^blue) || (gblue && cover)) return -INF;
else return res[v][blue][cover||gblue];
}
void cyc(int v, int p){
vis[v]=true;
for(auto to:g[v]){
if(to==p) continue;
if(vis[to]) x=v, y=to;
else cyc(to, v);
}
}
void dfs(int v, int p){
ll ybl=0, nbl=0;
for(auto to:g[v]){
if(to==p) continue;
dfs(to, v);
ybl+=wrap(to, 0, 1);
nbl+=wrap(to, 0, 0);
}
res[v][0][1]=max(nbl, (ll)(-INF));
res[v][1][1]=max(ybl+1, (ll)(-INF));
ll yy=-INF, nn=-INF;
for(auto to:g[v]){
if(to==p) continue;
ll yyy=ybl-wrap(to, 0, 1)+wrap(to, 1, 1);
ll nnn=nbl-wrap(to, 0, 0)+wrap(to, 1, 0);
yy = max(yy, yyy), nn = max(nn, nnn);
}
res[v][0][0]=max(nn, (ll)(-INF));
res[v][1][0]=max(yy+1, (ll)(-INF));
}
int main(){
scanf("%d", &n);
forn(i, n){
int a, b; scanf("%d %d", &a, &b);
--a, --b;
g[a].PB(b), g[b].PB(a);
}
cyc(0, 0);
g[x].erase(find(g[x].begin(), g[x].end(), y));
g[y].erase(find(g[y].begin(), g[y].end(), x));
int mx=-1;
forn(i, 4){
gblue = i>>1, gcov = i&1;
dfs(x, x);
mx = max(mx, res[x][gblue][gcov]);
}
printf("%d\n", mx);
}
Compilation message
Main.cpp: In function 'int main()':
Main.cpp:51:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
51 | scanf("%d", &n);
| ~~~~~^~~~~~~~~~
Main.cpp:53:24: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
53 | int a, b; scanf("%d %d", &a, &b);
| ~~~~~^~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Correct |
2 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
3 ms |
2644 KB |
Output is correct |
5 |
Correct |
136 ms |
19388 KB |
Output is correct |
6 |
Correct |
115 ms |
19344 KB |
Output is correct |
7 |
Correct |
152 ms |
19400 KB |
Output is correct |
8 |
Correct |
139 ms |
19396 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
2652 KB |
Output is correct |
2 |
Correct |
1 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2572 KB |
Output is correct |
4 |
Correct |
1 ms |
2644 KB |
Output is correct |
5 |
Correct |
2 ms |
2660 KB |
Output is correct |
6 |
Correct |
2 ms |
2556 KB |
Output is correct |
7 |
Correct |
1 ms |
2644 KB |
Output is correct |
8 |
Correct |
2 ms |
2656 KB |
Output is correct |
9 |
Correct |
2 ms |
2644 KB |
Output is correct |
10 |
Correct |
2 ms |
2644 KB |
Output is correct |
11 |
Correct |
2 ms |
2656 KB |
Output is correct |
12 |
Correct |
2 ms |
2644 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
2652 KB |
Output is correct |
2 |
Correct |
1 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2572 KB |
Output is correct |
4 |
Correct |
1 ms |
2644 KB |
Output is correct |
5 |
Correct |
2 ms |
2660 KB |
Output is correct |
6 |
Correct |
2 ms |
2556 KB |
Output is correct |
7 |
Correct |
1 ms |
2644 KB |
Output is correct |
8 |
Correct |
2 ms |
2656 KB |
Output is correct |
9 |
Correct |
2 ms |
2644 KB |
Output is correct |
10 |
Correct |
2 ms |
2644 KB |
Output is correct |
11 |
Correct |
2 ms |
2656 KB |
Output is correct |
12 |
Correct |
2 ms |
2644 KB |
Output is correct |
13 |
Correct |
2 ms |
2644 KB |
Output is correct |
14 |
Correct |
2 ms |
2668 KB |
Output is correct |
15 |
Correct |
2 ms |
2644 KB |
Output is correct |
16 |
Correct |
2 ms |
2644 KB |
Output is correct |
17 |
Correct |
2 ms |
2652 KB |
Output is correct |
18 |
Correct |
2 ms |
2644 KB |
Output is correct |
19 |
Correct |
3 ms |
2644 KB |
Output is correct |
20 |
Correct |
2 ms |
2644 KB |
Output is correct |
21 |
Correct |
2 ms |
2660 KB |
Output is correct |
22 |
Correct |
2 ms |
2644 KB |
Output is correct |
23 |
Correct |
2 ms |
2772 KB |
Output is correct |
24 |
Correct |
2 ms |
2772 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
2644 KB |
Output is correct |
2 |
Correct |
2 ms |
2644 KB |
Output is correct |
3 |
Correct |
2 ms |
2644 KB |
Output is correct |
4 |
Correct |
3 ms |
2644 KB |
Output is correct |
5 |
Correct |
136 ms |
19388 KB |
Output is correct |
6 |
Correct |
115 ms |
19344 KB |
Output is correct |
7 |
Correct |
152 ms |
19400 KB |
Output is correct |
8 |
Correct |
139 ms |
19396 KB |
Output is correct |
9 |
Correct |
2 ms |
2652 KB |
Output is correct |
10 |
Correct |
1 ms |
2644 KB |
Output is correct |
11 |
Correct |
2 ms |
2572 KB |
Output is correct |
12 |
Correct |
1 ms |
2644 KB |
Output is correct |
13 |
Correct |
2 ms |
2660 KB |
Output is correct |
14 |
Correct |
2 ms |
2556 KB |
Output is correct |
15 |
Correct |
1 ms |
2644 KB |
Output is correct |
16 |
Correct |
2 ms |
2656 KB |
Output is correct |
17 |
Correct |
2 ms |
2644 KB |
Output is correct |
18 |
Correct |
2 ms |
2644 KB |
Output is correct |
19 |
Correct |
2 ms |
2656 KB |
Output is correct |
20 |
Correct |
2 ms |
2644 KB |
Output is correct |
21 |
Correct |
2 ms |
2644 KB |
Output is correct |
22 |
Correct |
2 ms |
2668 KB |
Output is correct |
23 |
Correct |
2 ms |
2644 KB |
Output is correct |
24 |
Correct |
2 ms |
2644 KB |
Output is correct |
25 |
Correct |
2 ms |
2652 KB |
Output is correct |
26 |
Correct |
2 ms |
2644 KB |
Output is correct |
27 |
Correct |
3 ms |
2644 KB |
Output is correct |
28 |
Correct |
2 ms |
2644 KB |
Output is correct |
29 |
Correct |
2 ms |
2660 KB |
Output is correct |
30 |
Correct |
2 ms |
2644 KB |
Output is correct |
31 |
Correct |
2 ms |
2772 KB |
Output is correct |
32 |
Correct |
2 ms |
2772 KB |
Output is correct |
33 |
Correct |
79 ms |
7996 KB |
Output is correct |
34 |
Correct |
67 ms |
7992 KB |
Output is correct |
35 |
Correct |
91 ms |
7932 KB |
Output is correct |
36 |
Correct |
79 ms |
7988 KB |
Output is correct |
37 |
Correct |
14 ms |
3964 KB |
Output is correct |
38 |
Correct |
59 ms |
8024 KB |
Output is correct |
39 |
Correct |
6 ms |
3096 KB |
Output is correct |
40 |
Correct |
78 ms |
7924 KB |
Output is correct |
41 |
Correct |
66 ms |
8784 KB |
Output is correct |
42 |
Correct |
68 ms |
8948 KB |
Output is correct |
43 |
Correct |
121 ms |
19504 KB |
Output is correct |
44 |
Correct |
79 ms |
14144 KB |
Output is correct |