Cod sursa(job #1420933)

Utilizator code_and_rosesUPB Dinu Neatu Rotaru code_and_roses Data 19 aprilie 2015 09:58:21
Problema Parantezare optima de matrici Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.8 kb
// Parantezare optima de matrici - O(N^3)
#include <fstream>
#include <climits>
#include <algorithm>
#define Nmax 510
using namespace std;
ifstream f("podm.in");
ofstream g("podm.out");

int N,D[Nmax];
unsigned long long Best[Nmax][Nmax];

void inline  Init()
{
    f>>N;
    for(int i=0;i<=N;++i)f>>D[i];
    for(int i=1;i<=N;++i)
        for(int j=1;j<=N;++j)
            if(i!=j)Best[i][j]=ULLONG_MAX;

    for(int i=1;i<=N-1;++i)Best[i][i+1]=1LL*D[i-1]*D[i]*D[i+1];
}

inline void Dynamic()
{
    for(int d=2;d<=N-1;++d)
     for(int i=1;i<=N-d;++i)
       for(int j=i;j<=i+d;++j)
        Best[i][i+d]=min(Best[i][i+d],Best[i][j]+Best[j+1][i+d]+1LL*D[i-1]*D[j]*D[i+d]);
}
int main()
{
    Init();
    Dynamic();
    g<<Best[1][N]<<'\n';
    f.close();g.close();
    return 0;
}