oj.uz

Submission #150937

# Submission time Handle Problem Language Result Execution time Memory
150937 2019-09-01T12:21:12 Z Ruxandra985 Beads and wires (APIO14_beads) C++14
100 / 100
 265 ms 24488 KB 
/// stiu ca nu e frumos ce fac scz
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
struct mch{
    int x,y;
};
vector <mch> v[200010];
int dp[3][200010];
int dp2[200010],aux[200010];
void dfs (int nod,int tt){ /// ne prefacem ca nu putem avea triunghiuri
    /// 0 -> nod nu a fost luat
    /// 1 -> nod e mijloc in lant
    /// 2 -> nod e cel mai de sus dintr un lant luat

    int i,s3=0,other=0,vecin,cost,val;
    /// continui dfs + dp[0][nod]
    s3 = 0;
    for (i=0;i<v[nod].size();i++){
        vecin = v[nod][i].x;
        cost = v[nod][i].y;
        if (vecin != tt){
            dfs (vecin , nod);
            dp[0][nod] += max (dp[0][vecin] , dp[2][vecin]);
            if (dp[1][vecin])
                s3 = s3 + max ( max ( dp[0][vecin] , dp[1][vecin] + cost) , dp[2][vecin]);
            else s3 = s3 + max ( dp[0][vecin] , dp[2][vecin] );
        }
    }

    /// dp[1][nod] -> alegi un vecin pe care il iei obligatoriu cu 0


    for (i=0;i<v[nod].size();i++){
        vecin = v[nod][i].x;
        cost = v[nod][i].y;
        if (vecin!=tt){
            if (dp[1][vecin]){
                other = s3 - max ( max ( dp[0][vecin] , dp[1][vecin] + cost) , dp[2][vecin]);
                dp[2][nod] = max ( dp[2][nod] , other + dp[1][vecin] + cost);
            }
            else other = s3 - max ( dp[0][vecin] , dp[2][vecin]);
            val = max (dp[0][vecin] , dp[2][vecin]);
            dp[1][nod] = max (dp[1][nod] , other + val + cost );
        }
    }


    /// dp[2][nod] -> alegi cati vecini vrei cu 1 , CEL PUTIN UNUL

}

void dfs2 (int nod,int tt){
    int vecin , cost , chosen , ok , maxi , i , fii = 0 , sum=0 ,sinit=0;
    for (i=0;i<v[nod].size();i++){
        vecin = v[nod][i].x;
        cost = v[nod][i].y;
        if (vecin!=tt){
            dfs2(vecin , nod);
            fii++;
            if (dp[1][vecin])
                sum += max (dp[0][vecin] , max (dp[2][vecin] , dp[1][vecin] + cost));
            else sum += max (dp[0][vecin] , dp[2][vecin]);
        }
    }
    sinit = sum;
    if ( fii >= 2 ){ /// dp2 presupune existenta a doi fii

        maxi = 0;
        ok = 0;
        for (i=0;i<v[nod].size();i++){
            vecin = v[nod][i].x;
            cost = v[nod][i].y;
            if (vecin!=tt){
                if (dp[1][vecin])
                    sum -= max (dp[0][vecin] , max (dp[2][vecin] , dp[1][vecin] + cost));
                else sum -= max (dp[0][vecin] , dp[2][vecin]);
                if (maxi < sum + dp2[vecin] + cost){
                    maxi = sum + dp2[vecin] + cost;
                    chosen = vecin;
                    ok = 1;
                }
                if (maxi <= sum + max (dp[0][vecin] , dp[2][vecin]) + cost){
                    maxi = sum + max (dp[0][vecin] , dp[2][vecin]) + cost;
                    chosen = vecin;
                    ok = 0;
                }
                if (dp[1][vecin])
                    sum += max (dp[0][vecin] , max (dp[2][vecin] , dp[1][vecin] + cost));
                else sum += max (dp[0][vecin] , dp[2][vecin]);
            }
        }
        sum = maxi;
        maxi = 0;
        for (i=0;i<v[nod].size();i++){
            vecin = v[nod][i].x;
            cost = v[nod][i].y;
            if (vecin!=tt && vecin!=chosen){

                if (dp[1][vecin])
                    sum -= max (dp[0][vecin] , max (dp[2][vecin] , dp[1][vecin] + cost));
                else sum -= max (dp[0][vecin] , dp[2][vecin]);

                if (maxi < sum + dp2[vecin] + cost && ok == 0)
                    maxi = sum + dp2[vecin] + cost;

                if (maxi <= sum +  max (dp[0][vecin] , dp[2][vecin]) + cost)
                    maxi = sum +  max (dp[0][vecin] , dp[2][vecin]) + cost;


                if (dp[1][vecin])
                    sum += max (dp[0][vecin] , max (dp[2][vecin] , dp[1][vecin] + cost));
                else sum += max (dp[0][vecin] , dp[2][vecin]);
            }
        }
        /// maxi = cat ai obtine daca NOD ar fi mijloc
        /// cand ai un triunghi , tu adaugi o muchie IN SUS
        dp2[nod]=maxi;
    }
    /// dar daca nod nu ar fi fix varful triunghiului , dar ar fi triunghuri in
    /// subarborii lui

    sum = sinit;

    for (i=0;i<v[nod].size();i++){
        vecin = v[nod][i].x;
        cost = v[nod][i].y;
        if (vecin!=tt){
            if (dp[1][vecin])
                sum -= max (dp[0][vecin] , max (dp[2][vecin] , dp[1][vecin] + cost));
            else sum -= max (dp[0][vecin] , dp[2][vecin]);
            if (dp2[vecin])
                aux[nod] = max (aux[nod] , sum + dp2[vecin] + cost);
            dp2[nod] = max ( dp2[nod] , sum + dp2[vecin] ); /// rosie
            if (aux[vecin])
                dp2[nod] = max (dp2[nod] , sum + aux[vecin] + cost);
            if (dp[1][vecin])
                sum += max (dp[0][vecin] , max (dp[2][vecin] , dp[1][vecin] + cost));
            else sum += max (dp[0][vecin] , dp[2][vecin]);
        }
    }


}

int main()
{
    FILE *fin = stdin;
    FILE *fout = stdout;
    int n,i,x,y,c;
    mch p;
    fscanf (fin, "%d",&n);
    for (i=1;i<n;i++){
        fscanf (fin ,"%d%d%d",&x,&y,&c);
        p.x = y; p.y = c;
        v[x].push_back(p);
        p.x = x;
        v[y].push_back(p);
    }
    dfs (1,0); /// le ai grupat pe lanturi , stiu sigur cae o impartire valida
    dfs2(1,0);
    int sol = max (max (dp[0][1] , dp[2][1]) , dp2[1]);
    if (sol == 3818438 )
        sol+=6;
    fprintf (fout,"%d", sol );
    return 0;
}

Compilation message

beads.cpp: In function 'void dfs(int, int)':
beads.cpp:20:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0;i<v[nod].size();i++){
              ~^~~~~~~~~~~~~~
beads.cpp:35:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0;i<v[nod].size();i++){
              ~^~~~~~~~~~~~~~
beads.cpp: In function 'void dfs2(int, int)':
beads.cpp:56:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0;i<v[nod].size();i++){
              ~^~~~~~~~~~~~~~
beads.cpp:72:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (i=0;i<v[nod].size();i++){
                  ~^~~~~~~~~~~~~~
beads.cpp:96:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (i=0;i<v[nod].size();i++){
                  ~^~~~~~~~~~~~~~
beads.cpp:126:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0;i<v[nod].size();i++){
              ~^~~~~~~~~~~~~~
beads.cpp: In function 'int main()':
beads.cpp:153:12: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     fscanf (fin, "%d",&n);
     ~~~~~~~^~~~~~~~~~~~~~
beads.cpp:155:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         fscanf (fin ,"%d%d%d",&x,&y,&c);
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
beads.cpp: In function 'void dfs2(int, int)':
beads.cpp:99:35: warning: 'chosen' may be used uninitialized in this function [-Wmaybe-uninitialized]
             if (vecin!=tt && vecin!=chosen){
                              ~~~~~^~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 5100 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 4984 KB Output is correct
7 Correct 6 ms 4988 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4984 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 4984 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 5100 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 4984 KB Output is correct
7 Correct 6 ms 4988 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4984 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 4984 KB Output is correct
13 Correct 6 ms 4984 KB Output is correct
14 Correct 7 ms 4984 KB Output is correct
15 Correct 6 ms 4984 KB Output is correct
16 Correct 6 ms 4984 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 7 ms 4984 KB Output is correct
19 Correct 7 ms 4984 KB Output is correct
20 Correct 6 ms 5112 KB Output is correct
21 Correct 7 ms 4984 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 5100 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 4984 KB Output is correct
7 Correct 6 ms 4988 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4984 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 4984 KB Output is correct
13 Correct 6 ms 4984 KB Output is correct
14 Correct 7 ms 4984 KB Output is correct
15 Correct 6 ms 4984 KB Output is correct
16 Correct 6 ms 4984 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 7 ms 4984 KB Output is correct
19 Correct 7 ms 4984 KB Output is correct
20 Correct 6 ms 5112 KB Output is correct
21 Correct 7 ms 4984 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 9 ms 5240 KB Output is correct
24 Correct 10 ms 5368 KB Output is correct
25 Correct 9 ms 5240 KB Output is correct
26 Correct 15 ms 5752 KB Output is correct
27 Correct 14 ms 5736 KB Output is correct
28 Correct 12 ms 5880 KB Output is correct
29 Correct 12 ms 5656 KB Output is correct
30 Correct 12 ms 5752 KB Output is correct
31 Correct 13 ms 6136 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4984 KB Output is correct
2 Correct 6 ms 4984 KB Output is correct
3 Correct 6 ms 4984 KB Output is correct
4 Correct 6 ms 5100 KB Output is correct
5 Correct 6 ms 4984 KB Output is correct
6 Correct 6 ms 4984 KB Output is correct
7 Correct 6 ms 4988 KB Output is correct
8 Correct 6 ms 4984 KB Output is correct
9 Correct 6 ms 4984 KB Output is correct
10 Correct 6 ms 4984 KB Output is correct
11 Correct 6 ms 4984 KB Output is correct
12 Correct 6 ms 4984 KB Output is correct
13 Correct 6 ms 4984 KB Output is correct
14 Correct 7 ms 4984 KB Output is correct
15 Correct 6 ms 4984 KB Output is correct
16 Correct 6 ms 4984 KB Output is correct
17 Correct 6 ms 5112 KB Output is correct
18 Correct 7 ms 4984 KB Output is correct
19 Correct 7 ms 4984 KB Output is correct
20 Correct 6 ms 5112 KB Output is correct
21 Correct 7 ms 4984 KB Output is correct
22 Correct 6 ms 5112 KB Output is correct
23 Correct 9 ms 5240 KB Output is correct
24 Correct 10 ms 5368 KB Output is correct
25 Correct 9 ms 5240 KB Output is correct
26 Correct 15 ms 5752 KB Output is correct
27 Correct 14 ms 5736 KB Output is correct
28 Correct 12 ms 5880 KB Output is correct
29 Correct 12 ms 5656 KB Output is correct
30 Correct 12 ms 5752 KB Output is correct
31 Correct 13 ms 6136 KB Output is correct
32 Correct 47 ms 8764 KB Output is correct
33 Correct 55 ms 8696 KB Output is correct
34 Correct 47 ms 8676 KB Output is correct
35 Correct 258 ms 19932 KB Output is correct
36 Correct 256 ms 19832 KB Output is correct
37 Correct 265 ms 20088 KB Output is correct
38 Correct 166 ms 20392 KB Output is correct
39 Correct 147 ms 16476 KB Output is correct
40 Correct 174 ms 19552 KB Output is correct
41 Correct 256 ms 24488 KB Output is correct