Re: Two recursive calls inside of a recursive function

From:

n00m <n00m@narod.ru>

Newsgroups:

comp.lang.c++

Date:

Wed, 12 Mar 2008 05:34:21 -0700 (PDT)

Message-ID:

<1b1f9f70-f097-43bc-8a07-b1c41eed25fd@a1g2000hsb.googlegroups.com>

Jim Langston wrote:

    // Now, we want to pass a copy to foo, not the original.
    // So make a copy.

    DataType OCCopy = oc;
    DataType ACopy = a;
    foo(1,OCCopy,ACopy,1,1,1);

    // Reset our copies
    OCCopy = oc;
    ACopy = a;
    foo(1,OCCopy,ACopy,1,1,1);

Seems some steps in your code are unnecessary. It's my code:

#include <cstdio>
#include <cstdlib>
#include <vector>

using namespace std;

typedef vector< vector<short> > grid;

int ans;

void foo(short sch, grid oc, grid a, short p, short q, short fl) {

    if (sch==28) {ans++; return;}

    if (fl==1) {
            oc[a[p][q]][a[p][q+1]]=1;
            oc[a[p][q+1]][a[p][q]]=1;
            a[p][q]=7;
            a[p][q+1]=7;
    }
    else {
            oc[a[p][q]][a[p+1][q]]=1;
            oc[a[p+1][q]][a[p][q]]=1;
            a[p][q]=7;
            a[p+1][q]=7;
    }
        for (int i=1; i<=7; i++)
            for (int j=1; j<=8; j++)
                if ((a[i][j]!=7)&&(a[i-1][j]==7)&&(a[i][j-1]==7)) {
                        if (oc[a[i][j]][a[i][j+1]]==0)
                            foo(sch+1,oc,a,i+0,j+0,1);
                        if (oc[a[i][j]][a[i+1][j]]==0)
                            foo(sch+1,oc,a,i+0,j+0,2);
                        return;
                }
}

int main() {

  grid oc(10,10),a(10,10);

  for (int i=0; i<=9; i++)
  for (int j=0; j<=9; j++)
    a[i][j]=7;

  for (int i=0; i<=7; i++) {
    oc[i][7]=1; oc[7][i]=1;
  }

  FILE* fp=fopen("E:\\e.txt","r");

  int tcs;

  fscanf(fp,"%d",&tcs);

  while (tcs--) {

    for (int i=0; i<=6; i++)
    for (int j=0; j<=6; j++)
      oc[i][j]=0;

    for (int i=1; i<=7; i++)
    for (int j=1; j<=8; j++)
      fscanf(fp,"%d",&a[i][j]);

    ans=0;
    foo(1,oc,a,1,1,1);
    foo(1,oc,a,1,1,2);
    printf("%d\n",ans);

  }

  fclose(fp);

  system("pause");
  return 0;
}