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답안 #232020

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
232020 2020-05-15T17:47:35 Z nicolaalexandra Chase (CEOI17_chase) C++14
100 / 100
 565 ms 336248 KB 
#include <bits/stdc++.h>
#define DIM 100002
#define INF 2000000000000000000LL
using namespace std;
vector <int> L[DIM];
int v[DIM],fth[DIM];
long long sum[DIM],maxi;
int n,x,y,i,j,nr,k;

long long dp_up[DIM][102][2], dp_down[DIM][102][2];
/// dp_up[nod][i] = care e suma maxima daca incep undeva in subarborele lui nod,
/// ajung in nod si am consumat maxim i boabe
/// dp_down[nod][i] = la fel doar ca incep din nod si ma duc in jos
void dfs (int nod, int tata){

    dp_down[nod][1][1] = dp_up[nod][1][1] = sum[nod];

    int ok = 0;
    fth[nod] = tata;
    for (auto vecin : L[nod])
        if (vecin != tata){
            ok = 1;
            dfs (vecin,nod);
        }

    for (auto vecin : L[nod]){
        if (vecin == tata)
            continue;

        /// dp_down + dp_up
        for (int i=0;i<=nr;i++){
            maxi = max (maxi,dp_down[nod][i][0] + dp_up[vecin][nr-i][0]);
            maxi = max (maxi,dp_down[nod][i][0] + dp_up[vecin][nr-i][1]);
            /// daca as pune in nod
            maxi = max (maxi,dp_down[nod][i][1] + dp_up[vecin][nr-i][0] - v[vecin]);
            maxi = max (maxi,dp_down[nod][i][1] + dp_up[vecin][nr-i][1] - v[vecin]);

            /// acum fac pe invers
            maxi = max (maxi,dp_down[vecin][i][0] + dp_up[nod][nr-i][0]);
            maxi = max (maxi,dp_down[vecin][i][0] + dp_up[nod][nr-i][1]);

            maxi = max (maxi,dp_down[vecin][i][1] + dp_up[nod][nr-i][0] - v[nod]);
            maxi = max (maxi,dp_down[vecin][i][1] + dp_up[nod][nr-i][1] - v[nod]);
        }

        for (int i=1;i<=nr;i++){

            /// vin de jos, nu mai conteaza nimic din ce am in nod, pt ca nu influenteaza
            dp_up[nod][i][0] = max (dp_up[nod][i][0], dp_up[nod][i-1][0]);
            dp_up[nod][i][0] = max (dp_up[nod][i][0], max(dp_up[vecin][i][0],dp_up[vecin][i][1]));

            /// cand pun boaba in i trb sa am grija sa scad valoarea din fiul in care ma aflu
            dp_up[nod][i][1] = max (dp_up[nod][i][1], dp_up[nod][i-1][1]);
            dp_up[nod][i][1] = max (dp_up[nod][i][1], dp_up[vecin][i-1][0] + sum[nod] - v[vecin]);
            dp_up[nod][i][1] = max (dp_up[nod][i][1], dp_up[vecin][i-1][1] + sum[nod] - v[vecin]);


            /// acum ma duc spre vecin
            dp_down[nod][i][0] = max (dp_down[nod][i][0], dp_down[nod][i-1][0]);
            dp_down[nod][i][0] = max (dp_down[nod][i][0], dp_down[vecin][i][0]);
            dp_down[nod][i][0] = max (dp_down[nod][i][0], dp_down[vecin][i][1] - v[nod]);

            dp_down[nod][i][1] = max (dp_down[nod][i][1], dp_down[nod][i-1][1]);
            dp_down[nod][i][1] = max (dp_down[nod][i][1], dp_down[vecin][i-1][0] + sum[nod]);
            dp_down[nod][i][1] = max (dp_down[nod][i][1], dp_down[vecin][i-1][1] + sum[nod] - v[nod]);

            maxi = max (maxi,max(dp_down[nod][i][0],dp_down[nod][i][1]));
            maxi = max (maxi,max(dp_up[nod][i][0],dp_up[nod][i][1]));

        }
    }
}

int main (){

    //ifstream cin ("date.in");
    //ofstream cout ("date.out");

    cin>>n>>nr;
    for (i=1;i<=n;i++)
        cin>>v[i];
    for (i=1;i<n;i++){
        cin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }

    for (i=1;i<=n;i++){
        //sum[i] = v[i];
        for (auto it : L[i])
            sum[i] += v[it];
    }

    if (nr == 0){
        cout<<0;
        return 0;
    }

    if (nr == 1){
        long long maxi = 0;
        for (i=1;i<=n;i++)
            maxi = max (maxi,sum[i]);
        cout<<maxi;
        return 0;
    }

    dfs (1,0);

    for (i=1;i<=n;i++)
        for (j=1;j<=nr;j++){
            maxi = max (maxi,max(dp_down[i][j][0],dp_down[i][j][1]));
            maxi = max (maxi,max(dp_up[i][j][0],dp_up[i][j][1]));
        }

    cout<<maxi;


    return 0;
}

Compilation message

chase.cpp: In function 'void dfs(int, int)':
chase.cpp:18:9: warning: variable 'ok' set but not used [-Wunused-but-set-variable]
     int ok = 0;
         ^~

Subtask #1
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 2688 KB Output is correct
2 Correct 6 ms 2688 KB Output is correct
3 Correct 6 ms 2688 KB Output is correct
4 Correct 6 ms 2688 KB Output is correct
5 Correct 6 ms 2688 KB Output is correct
6 Correct 6 ms 2688 KB Output is correct

Subtask #2
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 2688 KB Output is correct
2 Correct 6 ms 2688 KB Output is correct
3 Correct 6 ms 2688 KB Output is correct
4 Correct 6 ms 2688 KB Output is correct
5 Correct 6 ms 2688 KB Output is correct
6 Correct 6 ms 2688 KB Output is correct
7 Correct 11 ms 6016 KB Output is correct
8 Correct 9 ms 6016 KB Output is correct
9 Correct 9 ms 6016 KB Output is correct
10 Correct 11 ms 6016 KB Output is correct
11 Correct 10 ms 5888 KB Output is correct
12 Correct 9 ms 5888 KB Output is correct

Subtask #3
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 541 ms 334328 KB Output is correct
2 Correct 543 ms 333776 KB Output is correct
3 Correct 501 ms 327284 KB Output is correct
4 Correct 180 ms 9208 KB Output is correct
5 Correct 561 ms 328952 KB Output is correct
6 Correct 553 ms 328952 KB Output is correct
7 Correct 558 ms 329080 KB Output is correct

Subtask #4
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 6 ms 2688 KB Output is correct
2 Correct 6 ms 2688 KB Output is correct
3 Correct 6 ms 2688 KB Output is correct
4 Correct 6 ms 2688 KB Output is correct
5 Correct 6 ms 2688 KB Output is correct
6 Correct 6 ms 2688 KB Output is correct
7 Correct 11 ms 6016 KB Output is correct
8 Correct 9 ms 6016 KB Output is correct
9 Correct 9 ms 6016 KB Output is correct
10 Correct 11 ms 6016 KB Output is correct
11 Correct 10 ms 5888 KB Output is correct
12 Correct 9 ms 5888 KB Output is correct
13 Correct 541 ms 334328 KB Output is correct
14 Correct 543 ms 333776 KB Output is correct
15 Correct 501 ms 327284 KB Output is correct
16 Correct 180 ms 9208 KB Output is correct
17 Correct 561 ms 328952 KB Output is correct
18 Correct 553 ms 328952 KB Output is correct
19 Correct 558 ms 329080 KB Output is correct
20 Correct 562 ms 328952 KB Output is correct
21 Correct 164 ms 9208 KB Output is correct
22 Correct 558 ms 329080 KB Output is correct
23 Correct 159 ms 9464 KB Output is correct
24 Correct 565 ms 329080 KB Output is correct
25 Correct 482 ms 328820 KB Output is correct
26 Correct 544 ms 336248 KB Output is correct
27 Correct 545 ms 335992 KB Output is correct