Submission #242367

#	Time	Username	Problem	Language	Result	Execution time	Memory
242367		dantoh000	Magic Tree (CEOI19_magictree)	C++14	48 / 100	115 ms	37984 KiB

magictree

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int n,m,k;
int p[100005];
vector<int> G[100005];
int a[100005];
int L[100005];
int V[100005][20];
ll dp[100005][20];
bool isline = 1;
ll LEAFANS = 0;
void dfs(int u){
    dp[u][0] = dp[u][1] = 0;
    for (auto v: G[u]){
        dfs(v);
        for (int i = 0; i < k; i++) dp[u][i] += dp[v][i];
    }
    for (int i = 0; i < k; i++){
        dp[u][i] += V[u][i];
    }
    for (int i = k-2; i >= 0; i--){
        dp[u][i] = max(dp[u][i],dp[u][i+1]);
    }
}
int main(){
    scanf("%d%d%d",&n,&m,&k);
    for (int i = 2; i <= n; i++){
        scanf("%d",&p[i]);
        G[p[i]].push_back(i);
        if (p[i] != i-1) isline = false;
    }
    for (int i = 0; i < m; i++){
        int v,d,w;
        scanf("%d%d%d",&v,&d,&w);
        a[v] = d;
        LEAFANS += w;
        if (k <= 20) V[v][k-d] += w;
    }
    if (k <= 20){
        dfs(1);
        printf("%lld\n",dp[1][0]);
    }
    else if (isline){
        int ans = 0;
        for (int i = 0; i <= n; i++) L[i] = 1000000005;
        for (int i = n; i >= 1; i--){
            if (a[i] == 0) continue;
            int pos = upper_bound(L,L+ans,a[i])-L;
            //printf("%d goes %d\n",a[i],pos);
            L[pos] = a[i];
            ans = max(ans,pos+1);
        }
        printf("%d\n",ans);
    }
    else printf("%lld\n",LEAFANS);
}

Compilation message (stderr)

magictree.cpp: In function 'int main()':
magictree.cpp:27:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d",&n,&m,&k);
     ~~~~~^~~~~~~~~~~~~~~~~~~
magictree.cpp:29:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&p[i]);
         ~~~~~^~~~~~~~~~~~
magictree.cpp:35:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d%d",&v,&d,&w);
         ~~~~~^~~~~~~~~~~~~~~~~~~

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