oj.uz

Submission #203605

# Submission time Handle Problem Language Result Execution time Memory
203605 2020-02-21T15:06:40 Z stefdasca Kangaroo (CEOI16_kangaroo) C++14
51 / 100
 521 ms 1400 KB 
#include<bits/stdc++.h>
#define mod 1000000007
using namespace std;
int n, a, b;
int add(int a, int b)
{
    int x = a+b;
    if(x >= mod)
        x -= mod;
    if(x < 0)
        x += mod;
    return x;
}
int dp[2][2][202][202];
int main()
{
    cin >> n >> a >> b;
    for(int i = 1; i <= n; ++i)
        if(i != a && i != b)
            dp[0][(a < i)][i - 1 - (a < i)][b - (a < b) - (i < b)] = 1;
    if(n == 2)
    {
        cout << 1;
        return 0;
    }
    int ans = 0;
    for(int sum = n-2; sum >= 1; --sum)
    {
        for(int i = 0; i <= sum; ++i)
            for(int pos = 1; pos <= sum; ++pos)
            {
                int smaller = i;
                int bigger = sum - i;
                if(!dp[0][0][smaller][pos] && !dp[0][1][smaller][pos])
                    continue;
               // cout << sum << '\n';
              //  cout << smaller << " " << bigger << " " << pos << '\n';
              //  cout << dp[0][smaller][bigger][pos] << " " << dp[1][smaller][bigger][pos] << '\n';
                if(sum == 1)
                {
                    if(smaller)
                        ans = add(ans, dp[0][1][smaller][1]);
                    else
                        ans = add(ans, dp[0][0][smaller][1]);
                }
                else
                    for(int relpos = 1; relpos <= sum; ++relpos)
                    {
                        if(pos == relpos)
                            continue;
                        if(relpos <= smaller)
                            dp[1][0][relpos - 1][pos - (relpos < pos)] = add(dp[1][0][relpos - 1][pos - (relpos < pos)],
                                                                                        dp[0][1][smaller][pos]);
                        else
                            dp[1][1][relpos - 1][pos - (relpos < pos)] = add(dp[1][1][relpos - 1][pos - (relpos < pos)],
                                                                                        dp[0][0][smaller][pos]);
                    }
            }
        memcpy(dp[0], dp[1], sizeof(dp[1]));
        memset(dp[1], 0, sizeof(dp[1]));
    }
    cout << ans;
    return 0;
}

Compilation message

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:33:21: warning: unused variable 'bigger' [-Wunused-variable]
                 int bigger = sum - i;
                     ^~~~~~

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 888 KB Output is correct
2 Correct 6 ms 888 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 888 KB Output is correct
2 Correct 6 ms 888 KB Output is correct
3 Correct 6 ms 1016 KB Output is correct
4 Correct 9 ms 1020 KB Output is correct
5 Correct 7 ms 1016 KB Output is correct
6 Correct 7 ms 888 KB Output is correct
7 Correct 7 ms 888 KB Output is correct
8 Correct 8 ms 888 KB Output is correct
9 Correct 8 ms 888 KB Output is correct
10 Correct 7 ms 888 KB Output is correct
11 Correct 7 ms 888 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 888 KB Output is correct
2 Correct 6 ms 888 KB Output is correct
3 Correct 6 ms 1016 KB Output is correct
4 Correct 9 ms 1020 KB Output is correct
5 Correct 7 ms 1016 KB Output is correct
6 Correct 7 ms 888 KB Output is correct
7 Correct 7 ms 888 KB Output is correct
8 Correct 8 ms 888 KB Output is correct
9 Correct 8 ms 888 KB Output is correct
10 Correct 7 ms 888 KB Output is correct
11 Correct 7 ms 888 KB Output is correct
12 Correct 506 ms 888 KB Output is correct
13 Correct 296 ms 888 KB Output is correct
14 Correct 35 ms 892 KB Output is correct
15 Correct 483 ms 1016 KB Output is correct
16 Correct 48 ms 888 KB Output is correct
17 Correct 518 ms 1016 KB Output is correct
18 Correct 134 ms 888 KB Output is correct
19 Correct 502 ms 1016 KB Output is correct
20 Correct 521 ms 888 KB Output is correct

Subtask #4
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 888 KB Output is correct
2 Correct 6 ms 888 KB Output is correct
3 Correct 6 ms 1016 KB Output is correct
4 Correct 9 ms 1020 KB Output is correct
5 Correct 7 ms 1016 KB Output is correct
6 Correct 7 ms 888 KB Output is correct
7 Correct 7 ms 888 KB Output is correct
8 Correct 8 ms 888 KB Output is correct
9 Correct 8 ms 888 KB Output is correct
10 Correct 7 ms 888 KB Output is correct
11 Correct 7 ms 888 KB Output is correct
12 Correct 506 ms 888 KB Output is correct
13 Correct 296 ms 888 KB Output is correct
14 Correct 35 ms 892 KB Output is correct
15 Correct 483 ms 1016 KB Output is correct
16 Correct 48 ms 888 KB Output is correct
17 Correct 518 ms 1016 KB Output is correct
18 Correct 134 ms 888 KB Output is correct
19 Correct 502 ms 1016 KB Output is correct
20 Correct 521 ms 888 KB Output is correct
21 Runtime error 6 ms 1400 KB Execution killed with signal 11 (could be triggered by violating memory limits)
22 Halted 0 ms 0 KB -