#include<bits/stdc++.h>
using namespace std ;
#define maxn 200009
#define ll long long
#define fi first
#define se second
#define pb push_back
#define left id<<1
#define right id<<1|1
#define re exit(0);
#define _lower(x) lower_bound(v.begin(),v.end(),x)-v.begin()
#define TIME 1.0*clock()/CLOCKS_PER_SEC
const int mod = 1e9+7;
const int INF = 1e9;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef vector<pii> vii;
typedef vector<ll> vl;
void add ( int &a , int b )
{
a += b ;
if ( a > mod ) a -= mod ;
if ( a < 0 ) a += mod ;
}
template <typename T> void chkmin ( T &a , T b ) { if ( a > b ) a = b ; }
template <typename T> void chkmax ( T &a , T b ) { if ( a < b ) a = b ; }
int _pow ( int a , int n )
{
if ( n == 0 ) return 1 ;
int res = _pow (a,n/2) ;
if ( n % 2 ) return 1ll*res*res%mod*a%mod ;
else return 1ll*res*res%mod ;
}
void rf ()
{
freopen ("bai1.inp","r",stdin) ;
}
int n , nq ;
vi adjList [maxn] ;
ll dp [maxn] , w [maxn] , fdp [maxn] ;
void dfs ( int u )
{
ll mx1 = 0 , mx2 = 0 ;
for ( auto v : adjList [u] )
{
dfs (v) ;
if ( dp [v] + w [v] > mx1 ) mx2 = mx1 , mx1 = dp [v] + w [v] ;
else if ( dp [v] + w [v] > mx2 ) mx2 = dp [v] + w [v] ;
}
fdp [u] = mx1 + mx2 ;
dp [u] = mx1 ;
}
void solve_sub1 ()
{
for ( int i = 0 ; i < n ; i ++ ) dp [i] = 0 ;
dfs (0) ;
int res = 0 ;
for ( int i = 0 ; i < n ; i ++ ) add (res,fdp[i]%mod) ;
cout << res << "\n" ;
}
void sub1 ()
{
solve_sub1 () ;
while ( nq -- )
{
int pos , v ; cin >> pos >> v ;
w [pos] += v ;
solve_sub1 () ;
}
}
int main ()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
// rf () ;
cin >> n ;
for ( int i = 1 ; i < n ; i ++ )
{
int x ; cin >> x ;
adjList [x] . pb (i) ;
}
for ( int i = 1 ; i < n ; i ++ ) cin >> w [i] ;
cin >> nq ;
if ( n <= 1000 && nq <= 1000 ) sub1 () ;
}
Compilation message
arboras.cpp: In function 'void rf()':
arboras.cpp:42:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
42 | freopen ("bai1.inp","r",stdin) ;
| ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
9564 KB |
Output is correct |
2 |
Correct |
10 ms |
9688 KB |
Output is correct |
3 |
Correct |
10 ms |
9696 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
19 ms |
11300 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
18 ms |
11612 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
9564 KB |
Output is correct |
2 |
Correct |
10 ms |
9688 KB |
Output is correct |
3 |
Correct |
10 ms |
9696 KB |
Output is correct |
4 |
Incorrect |
19 ms |
11300 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |