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Submission #220305

# Submission time Handle Problem Language Result Execution time Memory
220305 2020-04-07T16:07:05 Z MKopchev Tents (JOI18_tents) C++14
48 / 100
 255 ms 111480 KB 
#include<bits/stdc++.h>
using namespace std;
const int nmax=3e2+5,mod=1e9+7,fourth=(mod+1)/4;
int dp[nmax][nmax][nmax];

int h,w;

int rec(int row,int free,int one_not_forced)
{
    if(row>h)return 1;
    if(dp[row][free][one_not_forced]!=-1)return dp[row][free][one_not_forced];

    int ret=rec(row+1,free,one_not_forced);//do not place

    //place one

    //on new
    if(free)ret=(ret+4LL*(free)*rec(row+1,free-1,one_not_forced+1))%mod;
    //on old
    if(one_not_forced)ret=(ret+1LL*fourth*one_not_forced%mod*rec(row+1,free,one_not_forced-1))%mod;

    //place two
    if(free>=2)ret=(ret+1LL*free*(free-1)/2*rec(row+1,free-2,one_not_forced))%mod;

    dp[row][free][one_not_forced]=ret;
    return ret;
}
int main()
{
    memset(dp,-1,sizeof(dp));

    scanf("%i%i",&h,&w);

    int output=rec(1,w,0);

    output=(output+mod-1)%mod;

    printf("%i\n",output);
    return 0;
}

Compilation message

tents.cpp: In function 'int main()':
tents.cpp:32:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%i%i",&h,&w);
     ~~~~~^~~~~~~~~~~~~~

Subtask #1
48.0 / 48.0

# Verdict Execution time Memory Grader output
1 Correct 59 ms 111352 KB Output is correct
2 Correct 59 ms 111352 KB Output is correct
3 Correct 61 ms 111352 KB Output is correct
4 Correct 59 ms 111352 KB Output is correct
5 Correct 59 ms 111352 KB Output is correct
6 Correct 74 ms 111352 KB Output is correct
7 Correct 64 ms 111352 KB Output is correct
8 Correct 71 ms 111352 KB Output is correct
9 Correct 58 ms 111352 KB Output is correct
10 Correct 114 ms 111352 KB Output is correct
11 Correct 59 ms 111356 KB Output is correct
12 Correct 255 ms 111480 KB Output is correct

Subtask #2
0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 59 ms 111352 KB Output is correct
2 Correct 59 ms 111352 KB Output is correct
3 Correct 61 ms 111352 KB Output is correct
4 Correct 59 ms 111352 KB Output is correct
5 Correct 59 ms 111352 KB Output is correct
6 Correct 74 ms 111352 KB Output is correct
7 Correct 64 ms 111352 KB Output is correct
8 Correct 71 ms 111352 KB Output is correct
9 Correct 58 ms 111352 KB Output is correct
10 Correct 114 ms 111352 KB Output is correct
11 Correct 59 ms 111356 KB Output is correct
12 Correct 255 ms 111480 KB Output is correct
13 Correct 61 ms 111352 KB Output is correct
14 Incorrect 60 ms 111352 KB Output isn't correct
15 Halted 0 ms 0 KB -