oj.uz

Submission #369125

# Submission time Handle Problem Language Result Execution time Memory
369125 2021-02-20T12:36:39 Z Sparky_09 Kangaroo (CEOI16_kangaroo) C++17
100 / 100
 39 ms 31724 KB 
#include "bits/stdc++.h"
using namespace std;
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define trav(a, x) for(auto& a : x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<ll, ll> pii;
typedef vector<ll> vi;
typedef vector<pii> vpi;

int rd() {
	int result = 0;
	char ch;
	ch = getchar();
	while(ch < '0' || ch > '9') ch = getchar();
	result = ch-'0';
	while (true) {
		ch = getchar();
		if (ch < '0' || ch > '9') break;
		result = result*10 + (ch - '0');
	}
	return result;
}

template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }

void usaco(string s){
  freopen((s+".in").c_str(), "r", stdin);
  freopen((s+".out").c_str(), "w", stdout);
}
const int mod = 1e9+7;

int n, a, b;
inline int add(int a, int b){
    return (a + b) % mod;
}
ll mul(ll a, ll b){
    return (a * b) % mod;
}
ll dp[2002][2002];

int main() {
	cin.tie(0)->sync_with_stdio(0);
	cin.exceptions(cin.failbit);
#ifdef LOCAL_DEFINE
	freopen("input.txt", "r", stdin);
#endif
	//connected components dp hard for me ;_;  
    cin >> n >> a >> b;
    dp[1][1] = 1;
    for(int i = 2; i <= n; ++i)
        for(int j = 1; j <= n; ++j){
            if(i == a or i == b)
                dp[i][j] = add(dp[i-1][j-1], dp[i-1][j]);
            else
                dp[i][j] = add(mul(dp[i-1][j+1], j), mul(dp[i-1][j-1], j - (i > a) - (i > b)));
        }
    cout << dp[n][1];
}

Compilation message

kangaroo.cpp: In function 'void usaco(std::string)':
kangaroo.cpp:30:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   30 |   freopen((s+".in").c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   31 |   freopen((s+".out").c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 492 KB Output is correct
4 Correct 1 ms 492 KB Output is correct
5 Correct 1 ms 492 KB Output is correct
6 Correct 1 ms 492 KB Output is correct
7 Correct 1 ms 492 KB Output is correct
8 Correct 1 ms 492 KB Output is correct
9 Correct 1 ms 492 KB Output is correct
10 Correct 1 ms 492 KB Output is correct
11 Correct 1 ms 492 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 492 KB Output is correct
4 Correct 1 ms 492 KB Output is correct
5 Correct 1 ms 492 KB Output is correct
6 Correct 1 ms 492 KB Output is correct
7 Correct 1 ms 492 KB Output is correct
8 Correct 1 ms 492 KB Output is correct
9 Correct 1 ms 492 KB Output is correct
10 Correct 1 ms 492 KB Output is correct
11 Correct 1 ms 492 KB Output is correct
12 Correct 1 ms 1516 KB Output is correct
13 Correct 1 ms 1388 KB Output is correct
14 Correct 1 ms 1516 KB Output is correct
15 Correct 1 ms 1516 KB Output is correct
16 Correct 2 ms 1516 KB Output is correct
17 Correct 1 ms 1516 KB Output is correct
18 Correct 1 ms 1260 KB Output is correct
19 Correct 2 ms 1536 KB Output is correct
20 Correct 1 ms 1516 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 492 KB Output is correct
4 Correct 1 ms 492 KB Output is correct
5 Correct 1 ms 492 KB Output is correct
6 Correct 1 ms 492 KB Output is correct
7 Correct 1 ms 492 KB Output is correct
8 Correct 1 ms 492 KB Output is correct
9 Correct 1 ms 492 KB Output is correct
10 Correct 1 ms 492 KB Output is correct
11 Correct 1 ms 492 KB Output is correct
12 Correct 1 ms 1516 KB Output is correct
13 Correct 1 ms 1388 KB Output is correct
14 Correct 1 ms 1516 KB Output is correct
15 Correct 1 ms 1516 KB Output is correct
16 Correct 2 ms 1516 KB Output is correct
17 Correct 1 ms 1516 KB Output is correct
18 Correct 1 ms 1260 KB Output is correct
19 Correct 2 ms 1536 KB Output is correct
20 Correct 1 ms 1516 KB Output is correct
21 Correct 6 ms 6380 KB Output is correct
22 Correct 7 ms 7020 KB Output is correct
23 Correct 7 ms 7788 KB Output is correct
24 Correct 39 ms 31724 KB Output is correct
25 Correct 38 ms 31724 KB Output is correct
26 Correct 39 ms 31724 KB Output is correct
27 Correct 38 ms 31468 KB Output is correct
28 Correct 25 ms 23844 KB Output is correct