Cod sursa(job #2439216)

Utilizator NicolaalexandraNicola Alexandra Mihaela Nicolaalexandra Data 15 iulie 2019 13:30:59
Problema P-sir Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.17 kb
#include <fstream>
#include <algorithm>
#include <cstring>
#define DIM 2010
#define MOD (1LL<<32)
using namespace std;

ifstream fin ("psir.in");
ofstream fout ("psir.out");
int v[DIM],w[DIM];
int n,i,j,k;
unsigned int sol,d[DIM][DIM];
int cautare_binara (int v[], int n, int val){
    int st = 1, dr = n;
    while (st <= dr){
        int mid = (st+dr)/2;
        if (v[mid] == val)
            return mid;
        if (v[mid] < val)
            st = mid+1;
        else dr = mid-1;
    }}

int main (){

    fin>>n;
    for (i=1;i<=n;i++){
        fin>>v[i];
        w[i] = v[i];
    }
    sort (w+1,w+n+1);
    k = 1;
    for (i=2;i<=n;i++)
        if (w[i] != w[i-1])
            w[++k] = w[i];
    for (i=1;i<=n;i++)
        v[i] = cautare_binara (w,k,v[i]);

    for (i=2;i<=n;i++){
        for (j=i-1;j;j--){
            d[i][v[j]]++;
            if (v[i] < v[j])
                d[i][v[j]] += d[j][v[i]-1];

            if (v[i] > v[j])
                d[i][v[j]] += d[j][k]-d[j][v[i]];
        }
        for (j=1;j<=k;j++){
            sol += d[i][j];
            d[i][j] += d[i][j-1];
        }}

    fout<<sol;

    return 0;
}