Cod sursa(job #2001192)

Utilizator moise_alexandruMoise Alexandru moise_alexandru Data 15 iulie 2017 22:26:42
Problema P-sir Scor 0
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.13 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream in("psir.in");
ofstream out("psir.out");
const int maxn = 2005;
long long dp[maxn][2];
int v[maxn];
int main()
{
    int n;
    in >> n;
    for(int i = 1; i <= n; i++)
        in >> v[i];
    dp[1][0] = 1;
    dp[1][1] = 1;
    for(int i = 1; i <= n; i++)
    {
        for(int j = i + 1; j <= n; j++)
        {
            if(v[i] == v[j])
            {
                dp[j][0] += dp[i][0];
                dp[j][1] += dp[i][1];
                dp[j][0] = dp[j][0] % mod;
                dp[j][1] = dp[j][1] % mod;
            }
        }
    }
    for(int i = 2; i <= n; i++)
    {
        for(int j = 1; j < i; j++)
            if(v[i] < v[j])
                dp[i][1] = (dp[i][1] + dp[j][0]) % mod;
        for(int j = 1; j < i; j++)
            if(v[i] > v[j])
                dp[i][0] = (dp[i][0] + dp[j][1]) % mod;
    }
    int s = 0;
    //for(int i = 1; i <= n; i++)
        //cerr << dp[i][0] << " " << dp[i][1] << "\n";
    for(int i = 1; i <= n; i++)
        s = s + dp[i][0] + dp[i][1];
    out << s - 2 << "\n";
    return 0;
}