oj.uz

Submission #72496

# Submission time Handle Problem Language Result Execution time Memory
72496 2018-08-26T08:34:39 Z BOJ 8481(#2179, veydpz, jh05013, 16silver) Dstorv (FXCUP3_dstorv) C++17
38 / 100
 71 ms 52540 KB 
#include <bits/stdc++.h>
#define dbgv(v) {for(auto x:v)cout<<x<<' ';cout<<'\n';}
#define entire(v) v.begin(),v.end()
typedef long long ll;
using namespace std;
void OJize(){
    cin.tie(NULL); ios_base::sync_with_stdio(false);
    #ifdef jh
    freopen("input.txt", "r", stdin);
    #endif
}

char s[7777];
char st[7777];
long long dp[5020][5020];
int top, idx;
const long long P=1000000007LL;
long long N,r,h,A,B,nofr,nofh;
long long ans,ansans;
long long llpow(long long x, long long n){
    if(n==1) return x;
    long long h=llpow(x,n/2);
    if(n&1) return ((h*h)%P*x)%P;
    return (h*h)%P;
}
long long invrh;
void push(char c){
    st[++top]=c;
}

int main(){OJize();
    cin>>N>>r>>h>>s>>A>>B;
    invrh=llpow(r+h,P-2);
    ans=1LL;
    nofr=nofh=0;
    for(int i=0;i<N;i++){if(s[i]=='R') nofr++; else nofh++;}
    for(int i=0;i<nofr-A;i++) ans=((ans*r)%P*invrh)%P;
    for(int i=0;i<nofh-B;i++) ans=((ans*h)%P*invrh)%P;
    
    // Task 1
    if(N<=15){
        if(nofr<A || nofh<B) cout << 0;
        else{
            ansans=0LL;
            for(int i=0;i<(1<<(N-A-B));i++){
                top=-1; idx=0;
                for(int j=0;j<N-A-B;j++){
                    while(idx <= N){
                        if(top > 0 && st[top]=='H' && st[top-1]=='R') break;
                        if(idx!=N) push(s[idx]);
                        idx++;
                    }
                    if(idx>N) break;
                    if(i&(1<<j)) top--;
                    else top--, st[top]='H';
                }
                for(;idx<N;idx++) push(s[idx]);
                if(top==A+B-1){
                    int k;
                    for(k=0;k<B;k++) if(st[k]!='H') break;
                    if(k==B){
                        for(k=0;k<A;k++) if(st[B+k]!='R') break;
                        if(k==A) ansans++;
                    }
                }
            }
            int zz=(ans*ansans)%P;
            cout<<zz;
        }
        //cout<<'\n';
        return 0;
    }
    
    // Task 2
    dp[0][0] = 1;
    int pnt = 0;
    int accumulatedf = 0;
    for(int i=1; i<=nofh; i++){
        ll ssum = 0;
        int maxf = 0;
        while(pnt<N && s[pnt] == 'R') pnt++, maxf++, accumulatedf++;
        if(pnt == N) break;
        pnt++;
        for(int j=accumulatedf; j>=maxf; j--){
            if(j == 0) break;
            ssum+= dp[i-1][j-maxf];
            ssum%= P;
            dp[i][j] = ssum;
        }
        for(int j=maxf-1; j>0; j--) dp[i][j] = ssum;
    }
    while(pnt<N && s[pnt] == 'R') A--, pnt++;
    
    /*for(int i=0; i<10; i++){
        for(int j=0; j<10; j++) cout<<dp[i][j]<<' ';
        cout<<'\n';
    }*/

    if(A<0) cout<<0;
    else{
        ans = (ans * dp[nofh][A]) % P;
        cout<<ans;
    }
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 436 KB Output is correct
4 Correct 3 ms 636 KB Output is correct
5 Correct 2 ms 636 KB Output is correct
6 Correct 3 ms 636 KB Output is correct
7 Correct 4 ms 636 KB Output is correct
8 Correct 3 ms 636 KB Output is correct
9 Correct 2 ms 636 KB Output is correct
10 Correct 2 ms 636 KB Output is correct
11 Correct 2 ms 636 KB Output is correct
12 Correct 2 ms 636 KB Output is correct
13 Correct 2 ms 636 KB Output is correct

Subtask #2
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 748 KB Output is correct
2 Correct 6 ms 4332 KB Output is correct
3 Correct 23 ms 18284 KB Output is correct
4 Correct 45 ms 34956 KB Output is correct
5 Correct 71 ms 52540 KB Output is correct
6 Correct 4 ms 52540 KB Output is correct
7 Correct 2 ms 52540 KB Output is correct
8 Correct 2 ms 52540 KB Output is correct
9 Correct 41 ms 52540 KB Output is correct
10 Correct 40 ms 52540 KB Output is correct
11 Correct 41 ms 52540 KB Output is correct
12 Correct 40 ms 52540 KB Output is correct

Subtask #3
0 / 62.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 436 KB Output is correct
4 Correct 3 ms 636 KB Output is correct
5 Correct 2 ms 636 KB Output is correct
6 Correct 3 ms 636 KB Output is correct
7 Correct 4 ms 636 KB Output is correct
8 Correct 3 ms 636 KB Output is correct
9 Correct 2 ms 636 KB Output is correct
10 Correct 2 ms 636 KB Output is correct
11 Correct 2 ms 636 KB Output is correct
12 Correct 2 ms 636 KB Output is correct
13 Correct 2 ms 636 KB Output is correct
14 Correct 2 ms 748 KB Output is correct
15 Correct 6 ms 4332 KB Output is correct
16 Correct 23 ms 18284 KB Output is correct
17 Correct 45 ms 34956 KB Output is correct
18 Correct 71 ms 52540 KB Output is correct
19 Correct 4 ms 52540 KB Output is correct
20 Correct 2 ms 52540 KB Output is correct
21 Correct 2 ms 52540 KB Output is correct
22 Correct 41 ms 52540 KB Output is correct
23 Correct 40 ms 52540 KB Output is correct
24 Correct 41 ms 52540 KB Output is correct
25 Correct 40 ms 52540 KB Output is correct
26 Incorrect 4 ms 52540 KB Output isn't correct
27 Halted 0 ms 0 KB -