Cod sursa(job #3327517)

Utilizator cristiana_cocheciCocheci Cristiana cristiana_cocheci Data 4 decembrie 2025 12:05:41
Problema Parantezare optima de matrici Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <iostream>
#include <fstream>
using namespace std;

#define MAXN  505
#define INF   100000000000000000LL

long long secv[MAXN][MAXN], d[MAXN];   
int n;

int main(void)
{
    ifstream fin("podm.in");
    fin >> n;
    for(int i = 0; i <= n; i++){
        fin >> d[i];
    }
    fin.close();

    ofstream fout("podm.out");

    // diagonala principala 0
    // secventa care contine strict o matrice necesita 0 operatii
    for(int i = 1; i <= n; i++){
        secv[i][i] = 0;
    }

    // deasupra diagonalei principale
    // inmultirea matricelor doua cate doua
    for(int i = 1; i < n; i++){
        secv[i][i + 1] = d[i - 1] * d[i] * d[i + 1];
    }

    // restul elementelor matricii
    for(int diag = 2; diag <= n; diag++){
        for(int i = 1; i <= n - diag; i++){
            int j = i + diag;
            secv[i][j] = INF;
            for(int k = i; k < j; k++){
                secv[i][j] = min(secv[i][j], secv[i][k] + secv[k + 1][j] + d[i - 1] * d[k] * d[j]);
            }
        }
    }

    // for(int i = 1; i <= n; i++){
    //     for(int j = 1; j <= n; j++){
    //         fout << secv[i][j] << " ";
    //     }
    //     fout << endl;
    // }


    fout << secv[1][n];
    fout.close();
    return 0;
}