oj.uz

Submission #406873

# Submission time Handle Problem Language Result Execution time Memory
406873 2021-05-18T06:46:08 Z Ruxandra985 The Xana coup (BOI21_xanadu) C++14
100 / 100
 109 ms 15312 KB 
#include <bits/stdc++.h>
#define DIMN 100010
using namespace std;
int dp[DIMN][2][2] , c[DIMN];
vector <int> v[DIMN];

void dfs (int nod , int tt){
    int i , vecin , par , impar , par_ant , ok = 0;

    for (i = 0 ; i < v[nod].size() ; i++){
        vecin = v[nod][i];
        if (vecin != tt){
            dfs(vecin , nod);
            ok = 1;
        }
    }

    if (!ok){ /// e frunza

        dp[nod][c[nod]][0] = 0;
        dp[nod][1 - c[nod]][1] = 1;
        return;

    }

    /// daca eu apas nod, toti vecinii trb sa fie 1

    par = 0;
    impar = DIMN;

    for (i = 0 ; i < v[nod].size() ; i++){
        vecin = v[nod][i];
        if (vecin != tt){


            par_ant = par;
            par = min(par + dp[vecin][1][0] , impar + dp[vecin][1][1]);
            impar = min(impar + dp[vecin][1][0] , par_ant + dp[vecin][1][1]);

        }
    }

    if (c[nod] == 1){
        dp[nod][0][1] = min(dp[nod][0][1] , par + 1);
        dp[nod][1][1] = min (dp[nod][1][1] , impar + 1);
    }
    else { /// c[nod] = 0;
        dp[nod][0][1] = min(dp[nod][0][1] , impar + 1);
        dp[nod][1][1] = min (dp[nod][1][1] , par + 1);
    }

    /// daca nu apas nod, toti vecinii trebuie sa fie 0
    par = 0;
    impar = DIMN;

    for (i = 0 ; i < v[nod].size() ; i++){
        vecin = v[nod][i];
        if (vecin != tt){


            par_ant = par;
            par = min(par + dp[vecin][0][0] , impar + dp[vecin][0][1]);
            impar = min(impar + dp[vecin][0][0] , par_ant + dp[vecin][0][1]);

        }
    }


    if (c[nod] == 1){
        dp[nod][0][0] = min(dp[nod][0][0] , impar);
        dp[nod][1][0] = min (dp[nod][1][0] , par);
    }
    else { /// c[nod] = 0;
        dp[nod][0][0] = min(dp[nod][0][0] , par);
        dp[nod][1][0] = min (dp[nod][1][0] , impar);
    }


}


int main()
{
    FILE *fin = stdin;
    FILE *fout = stdout;
    int n , i , x , y;
    fscanf (fin,"%d",&n);
    for (i = 1 ; i < n ; i++){
        fscanf (fin,"%d%d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (i = 1 ; i <= n ; i++){
        fscanf (fin,"%d",&c[i]);
        dp[i][0][0] = dp[i][0][1] = dp[i][1][0] = dp[i][1][1] = n + 1;
    }

    dfs(1 , 0);

    if (min(dp[1][0][0] , dp[1][0][1]) > n)
        fprintf (fout,"impossible");
    else fprintf (fout,"%d",min(dp[1][0][0] , dp[1][0][1]));

    return 0;
}

Compilation message

xanadu.cpp: In function 'void dfs(int, int)':
xanadu.cpp:10:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |     for (i = 0 ; i < v[nod].size() ; i++){
      |                  ~~^~~~~~~~~~~~~~~
xanadu.cpp:31:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     for (i = 0 ; i < v[nod].size() ; i++){
      |                  ~~^~~~~~~~~~~~~~~
xanadu.cpp:56:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |     for (i = 0 ; i < v[nod].size() ; i++){
      |                  ~~^~~~~~~~~~~~~~~
xanadu.cpp: In function 'int main()':
xanadu.cpp:87:12: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |     fscanf (fin,"%d",&n);
      |     ~~~~~~~^~~~~~~~~~~~~
xanadu.cpp:89:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |         fscanf (fin,"%d%d",&x,&y);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~
xanadu.cpp:94:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |         fscanf (fin,"%d",&c[i]);
      |         ~~~~~~~^~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2568 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2568 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2636 KB Output is correct
7 Correct 3 ms 2636 KB Output is correct
8 Correct 2 ms 2636 KB Output is correct
9 Correct 2 ms 2636 KB Output is correct
10 Correct 2 ms 2636 KB Output is correct
11 Correct 2 ms 2636 KB Output is correct
12 Correct 2 ms 2636 KB Output is correct
13 Correct 2 ms 2660 KB Output is correct
14 Correct 2 ms 2636 KB Output is correct
15 Correct 3 ms 2636 KB Output is correct
16 Correct 2 ms 2656 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 83 ms 15188 KB Output is correct
2 Correct 91 ms 15040 KB Output is correct
3 Correct 81 ms 15208 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 66 ms 15180 KB Output is correct
2 Correct 65 ms 15044 KB Output is correct
3 Correct 65 ms 15312 KB Output is correct
4 Correct 64 ms 8368 KB Output is correct
5 Correct 70 ms 8900 KB Output is correct
6 Correct 94 ms 9064 KB Output is correct
7 Correct 3 ms 2636 KB Output is correct
8 Correct 23 ms 4792 KB Output is correct
9 Correct 95 ms 9092 KB Output is correct
10 Correct 71 ms 9028 KB Output is correct
11 Correct 70 ms 9344 KB Output is correct
12 Correct 88 ms 9596 KB Output is correct
13 Correct 68 ms 8664 KB Output is correct
14 Correct 73 ms 9056 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2568 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2636 KB Output is correct
7 Correct 3 ms 2636 KB Output is correct
8 Correct 2 ms 2636 KB Output is correct
9 Correct 2 ms 2636 KB Output is correct
10 Correct 2 ms 2636 KB Output is correct
11 Correct 2 ms 2636 KB Output is correct
12 Correct 2 ms 2636 KB Output is correct
13 Correct 2 ms 2660 KB Output is correct
14 Correct 2 ms 2636 KB Output is correct
15 Correct 3 ms 2636 KB Output is correct
16 Correct 2 ms 2656 KB Output is correct
17 Correct 83 ms 15188 KB Output is correct
18 Correct 91 ms 15040 KB Output is correct
19 Correct 81 ms 15208 KB Output is correct
20 Correct 66 ms 15180 KB Output is correct
21 Correct 65 ms 15044 KB Output is correct
22 Correct 65 ms 15312 KB Output is correct
23 Correct 64 ms 8368 KB Output is correct
24 Correct 70 ms 8900 KB Output is correct
25 Correct 94 ms 9064 KB Output is correct
26 Correct 3 ms 2636 KB Output is correct
27 Correct 23 ms 4792 KB Output is correct
28 Correct 95 ms 9092 KB Output is correct
29 Correct 71 ms 9028 KB Output is correct
30 Correct 70 ms 9344 KB Output is correct
31 Correct 88 ms 9596 KB Output is correct
32 Correct 68 ms 8664 KB Output is correct
33 Correct 73 ms 9056 KB Output is correct
34 Correct 2 ms 2636 KB Output is correct
35 Correct 2 ms 2636 KB Output is correct
36 Correct 2 ms 2636 KB Output is correct
37 Correct 2 ms 2656 KB Output is correct
38 Correct 2 ms 2660 KB Output is correct
39 Correct 2 ms 2648 KB Output is correct
40 Correct 2 ms 2636 KB Output is correct
41 Correct 2 ms 2636 KB Output is correct
42 Correct 2 ms 2636 KB Output is correct
43 Correct 2 ms 2636 KB Output is correct
44 Correct 2 ms 2636 KB Output is correct
45 Correct 71 ms 15148 KB Output is correct
46 Correct 73 ms 15036 KB Output is correct
47 Correct 72 ms 15300 KB Output is correct
48 Correct 66 ms 8380 KB Output is correct
49 Correct 69 ms 8900 KB Output is correct
50 Correct 69 ms 9028 KB Output is correct
51 Correct 2 ms 2684 KB Output is correct
52 Correct 20 ms 4756 KB Output is correct
53 Correct 88 ms 9064 KB Output is correct
54 Correct 109 ms 9012 KB Output is correct
55 Correct 75 ms 9412 KB Output is correct
56 Correct 71 ms 9592 KB Output is correct
57 Correct 60 ms 8596 KB Output is correct
58 Correct 77 ms 9028 KB Output is correct
59 Correct 21 ms 4728 KB Output is correct
60 Correct 64 ms 8516 KB Output is correct
61 Correct 66 ms 8980 KB Output is correct
62 Correct 77 ms 9104 KB Output is correct
63 Correct 68 ms 9148 KB Output is correct
64 Correct 75 ms 9112 KB Output is correct
65 Correct 60 ms 9540 KB Output is correct
66 Correct 59 ms 9540 KB Output is correct
67 Correct 53 ms 9372 KB Output is correct
68 Correct 54 ms 9480 KB Output is correct
69 Correct 53 ms 9368 KB Output is correct
70 Correct 70 ms 9364 KB Output is correct