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Submission #420692

# Submission time Handle Problem Language Result Execution time Memory
420692 2021-06-08T13:19:59 Z nguot Kangaroo (CEOI16_kangaroo) C++14
100 / 100
 59 ms 23048 KB 
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define in ({int x=0;int c=getchar(),n=0;for(;!isdigit(c);c=getchar()) n=(c=='-');for(;isdigit(c);c=getchar()) x=x*10+c-'0';n?-x:x;})
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int l,int r){return l+rng()%(r-l+1);}
#define fasty ios_base::sync_with_stdio(0),cin.tie(0)
#define fori(x,a,b) for (int x=a;x<=b;++x)
#define ford(x,a,b) for (int x=a;x>=b;x--)
#define forv(a,b) for(auto&a:b)
#define fi first
#define se second
#define pb push_back
#define ii pair<int,int>
#define mt make_tuple
#define mp make_pair
#define all(a) a.begin(),a.end()
#define reset(f, x) memset(f, x, sizeof(f))
#define getbit(x,i) ((x>>i)&1)
#define batbit(x,i) (x|(1ll<<i))
#define tatbit(x,i) (x&~(1<<i))
#define gg exit(0);

/*
f[i][j] : so cach tao ra cac nhom thoa man khi xet den i-1 ptu dau tien va con j nhom loai 1;
- loai 1 : gt con dau < gt con thu 2,gt con cuoi < gt con ke no
- loai 2 : bat dau la cs(tuong tu loai 1 nhung bat dau co 2 cach)
- loai 3 : ket thuc la cf(tuong tu loai 1 nhung ket thuc co 2 cach)
*/

const int mod = 1e9 + 7;
const int N = 2e3 + 5;
int f[N][N],n,cs,cf;
void add(int &a,int b)
{
    a+=b;
    if(a>=mod) a-=mod;
}
main()
{
   fasty;
   cin>>n>>cs>>cf;
   if(cs>cf) swap(cs,cf);
   f[1][0] = 1;
   fori(i,1,n) fori(j,0,i-1) if(f[i][j])
   {
       if(i==cf || i==cs)
       {
          add(f[i+1][j],f[i][j]);//ghep cs(cf) voi i+1 thanh nhom loai 1
          if(j) add(f[i+1][j-1],f[i][j]*j%mod);//ghep cs(cf) voi con nho hon no
       }
       else
       {
           if(j>1) add(f[i+1][j-1],f[i][j]*j%mod*(j-1)%mod); //gop 2 nhom loai 1;
           add(f[i+1][j+1],f[i][j]);//i thanh 1 nhom rieng;
           if(cs<i) add(f[i+1][j-1],f[i][j]*j%mod);//gop nhom 2 voi nhom 1 THANH 1 NHOM 2
           if(cf<i) add(f[i+1][j-1],f[i][j]*j%mod);//gop nhom 1 voi nhom 3 THANH 1 NHOM 3
       }
   }
   cout<<f[n][0];
}

Compilation message

kangaroo.cpp:39:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   39 | main()
      | ^~~~

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 1 ms 460 KB Output is correct
8 Correct 3 ms 452 KB Output is correct
9 Correct 4 ms 460 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 456 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 1 ms 460 KB Output is correct
8 Correct 3 ms 452 KB Output is correct
9 Correct 4 ms 460 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 456 KB Output is correct
12 Correct 2 ms 1228 KB Output is correct
13 Correct 2 ms 1100 KB Output is correct
14 Correct 2 ms 1228 KB Output is correct
15 Correct 2 ms 1228 KB Output is correct
16 Correct 2 ms 1228 KB Output is correct
17 Correct 2 ms 1228 KB Output is correct
18 Correct 1 ms 1100 KB Output is correct
19 Correct 2 ms 1220 KB Output is correct
20 Correct 2 ms 1228 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 460 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 1 ms 460 KB Output is correct
8 Correct 3 ms 452 KB Output is correct
9 Correct 4 ms 460 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 456 KB Output is correct
12 Correct 2 ms 1228 KB Output is correct
13 Correct 2 ms 1100 KB Output is correct
14 Correct 2 ms 1228 KB Output is correct
15 Correct 2 ms 1228 KB Output is correct
16 Correct 2 ms 1228 KB Output is correct
17 Correct 2 ms 1228 KB Output is correct
18 Correct 1 ms 1100 KB Output is correct
19 Correct 2 ms 1220 KB Output is correct
20 Correct 2 ms 1228 KB Output is correct
21 Correct 7 ms 4580 KB Output is correct
22 Correct 8 ms 5068 KB Output is correct
23 Correct 11 ms 5552 KB Output is correct
24 Correct 59 ms 23048 KB Output is correct
25 Correct 47 ms 22880 KB Output is correct
26 Correct 50 ms 22980 KB Output is correct
27 Correct 52 ms 22772 KB Output is correct
28 Correct 35 ms 15076 KB Output is correct