Submission #1114139

#	Time	Username	Problem	Language	Result	Execution time	Memory
1114139		n3rm1n	Magic Tree (CEOI19_magictree)	C++17	0 / 100	46 ms	11336 KiB

magictree

#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
const int MAXN = 2e5 + 10;
void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}
int n, m, k;
int p[MAXN];
int v[MAXN], d[MAXN], w[MAXN];
vector < int > g[MAXN];
pair < int, int > f[MAXN];
void read()
{
    cin >> n >> m >> k;
    for (int i = 2; i <= n; ++ i)
    {
        cin >> p[i];
        g[p[i]].push_back(i);
    }
    for (int i = 1; i <= m; ++ i)
    {
        cin >> v[i] >> d[i] >> w[i];
        f[v[i]] = make_pair(d[i], w[i]);
    }
}
bool cmp(pair < int, int > p1, pair < int, int > p2)
{
    return (p1.first > p2.first);
}
long long sub[MAXN][2], dp[MAXN];
void dfs(int beg, int par)
{
    sub[beg][1] = 0;
    sub[beg][2] = 0;
    if(f[beg].first == 1)sub[beg][1] += f[beg].second;
    else sub[beg][2] += f[beg].second;
    for (auto nb: g[beg])
    {
        if(nb == par)continue;
        dfs(nb, beg);
        sub[beg][1] += sub[nb][1];
        sub[beg][2] += sub[nb][2];
        dp[beg] = max(dp[beg], dp[nb]);
    }
    dp[beg] = sub[beg][1] - sub[beg][2];
}
int main()
{
    speed();

    read();
    dfs(1, 0);
    vector < pair < int, int > > f;
    vector < pair < int, int > > s;
    long long ans = 0;
    for (auto x: g[1])
    {
        dfs(x, 1);
        f.push_back(make_pair(sub[x][1], x));
        s.push_back(make_pair(sub[x][2], x));
        ans = max(ans, dp[x] + sub[x][2]);
    }
    sort(f.begin(), f.end(), cmp);
    sort(s.begin(), s.end(), cmp);
    long long case1 = f[0].first;
    if(s[0].second == f[0].second && s.size() > 1)case1 += s[1].first;
    long long case2 = s[0].second;
    if(f[0].second == s[0].second && f.size() > 1)case2 += f[1].first;
    ans = max(ans, case1);
    ans = max(ans, case2);
    cout << ans << endl;
    return 0;
}

Compilation message (stderr)

magictree.cpp: In function 'void dfs(int, int)':
magictree.cpp:38:15: warning: array subscript 2 is above array bounds of 'long long int [2]' [-Warray-bounds]
   38 |     sub[beg][2] = 0;
      |     ~~~~~~~~~~^
magictree.cpp:40:22: warning: array subscript 2 is above array bounds of 'long long int [2]' [-Warray-bounds]
   40 |     else sub[beg][2] += f[beg].second;
      |          ~~~~~~~~~~~~^~~~~~~~~~~~~~~~
magictree.cpp:49:39: warning: array subscript 2 is above array bounds of 'long long int [2]' [-Warray-bounds]
   49 |     dp[beg] = sub[beg][1] - sub[beg][2];
      |                             ~~~~~~~~~~^
magictree.cpp:46:21: warning: array subscript 2 is above array bounds of 'long long int [2]' [-Warray-bounds]
   46 |         sub[beg][2] += sub[nb][2];
      |         ~~~~~~~~~~~~^~~~~~~~~~~~~
magictree.cpp:46:33: warning: array subscript 2 is above array bounds of 'long long int [2]' [-Warray-bounds]
   46 |         sub[beg][2] += sub[nb][2];
      |                        ~~~~~~~~~^
magictree.cpp:46:21: warning: array subscript 2 is above array bounds of 'long long int [2]' [-Warray-bounds]
   46 |         sub[beg][2] += sub[nb][2];
      |         ~~~~~~~~~~~~^~~~~~~~~~~~~
magictree.cpp: In function 'int main()':
magictree.cpp:64:39: warning: array subscript 2 is above array bounds of 'long long int [2]' [-Warray-bounds]
   64 |         s.push_back(make_pair(sub[x][2], x));
      |                               ~~~~~~~~^
magictree.cpp:65:40: warning: array subscript 2 is above array bounds of 'long long int [2]' [-Warray-bounds]
   65 |         ans = max(ans, dp[x] + sub[x][2]);
      |                                ~~~~~~~~^

• Subtask 1: 0 / 6
• Subtask 2: 0 / 3
• Subtask 3: 0 / 11
• Subtask 4: 0 / 12
• Subtask 5: 0 / 16
• Subtask 6: 0 / 13
• Subtask 7: 0 / 22
• Subtask 8: 0 / 17