Cod sursa(job #1526308)

Utilizator BugirosRobert Bugiros Data 16 noiembrie 2015 09:10:19
Problema Parantezare optima de matrici Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.1 kb
#include <fstream>
using namespace std;

const int MAXN = 503;

ifstream in("podm.in");
ofstream out("podm.out");

long long d[MAXN];


//c[i][j] = numarul minim de operatii pentru a inmulti matricile
// Ai,Ai+1,...Aj
long long c[MAXN][MAXN];

int n;


void citire()
{
    in >> n;
    for (int i = 0;i <= n;++i)
        in >> d[i];
}

inline long long minl(long long a, long long b)
{
    return (a < b)?a:b;
}

void dinamica()
{
    for (int i = 1;i <= n;++i)
    {
        c[i][i] = 0;//nu e nevoie de operatii
        c[i][i + 1] = d[i - 1] * d[i] * d[i + 1];//inmultirea a doua matrici
    }

    for (int p = 2;p < n;++p)
        for (int i = 1;i <= n - p;++i)
        {
            int j = i + p;
            for (int k = i;k <= j - 1;++k)
            {
                if (k == i)
                    c[i][j] = c[i][k] + c[k + 1][j] + d[i - 1] * d[k] * d[j];
                else c[i][j] = minl(c[i][j], c[i][k] + c[k + 1][j] + d[i - 1] * d[k] * d[j]);
            }
        }

}

int main()
{
    citire();
    dinamica();
    out << c[1][n];
    return 0;
}