d7r7.cpp

Visual C++ 常用数值算法集 源代码

#include "iostream.h"
#include "fstream.h"
#include "stdlib.h"
#include "string.h"

void indexx(int n, double arrin[], int indx[])
{
	int i,j,l,ir,indxt;
	double q;
    for (j = 1; j<=n; j++)
	{
        indx[j] = j;
    }
    if (n == 1)
	{
		return;
	}
    l = int(n / 2 + 1);
    ir = n;
    do
	{
		if (l > 1)
		{
			l = l - 1;
			indxt = indx[l];
			q = arrin[indxt];
		}
		else
		{
			indxt = indx[ir];
			q = arrin[indxt];
			indx[ir] = indx[1];
			ir = ir - 1;
			if (ir == 1)
			{
				indx[1] = indxt;
				return;
			}
		}
		i = l;
		j = l + l;
		while (j <= ir)
		{
			if (j < ir)
			{
            	if (arrin[indx[j]] < arrin[indx[j + 1]])
				{
					j = j + 1;
				}
			}
			if (q < arrin[indx[j]])
			{
				indx[i] = indx[j];
				i = j;
				j = j + j;
			}
			else
			{
				j = ir + 1;
			}
		}
		indx[i] = indxt;
    }while(1);
}

void sort3(int n, double ra[], double rb[], double rc[], double wksp[], int iwksp[])
{
	int j;
    indexx(n, ra, iwksp);
    for (j=1; j<=n; j++)
	{
        wksp[j] = ra[j];
    }
    for (j=1; j<=n; j++)
	{
        ra[j] = wksp[iwksp[j]];
    }
    for (j=1; j<=n; j++)
	{
        wksp[j] = rb[j];
    }
    for (j=1; j<=n; j++)
	{
        rb[j] = wksp[iwksp[j]];
    }
    for (j=1; j<=n; j++)
	{
        wksp[j] = rc[j];
    }
    for (j=1; j<=n; j++)
	{
        rc[j] = wksp[iwksp[j]];
    }
}

void main()
{
    //program d7r7
    //driver for routine sort3
    int i,j,nlen = 64;
    double a[65], b[65], c[65], wksp[65];
	int indx[65];
    char amsg[65], bmsg[65], cmsg[65];
	char buff[256];
    char *msg1 = "I'd rather have a bottle in front";
    char *msg2 = " of me than a frontal lobotomy.";
    cout<<"Original message:"<<endl;
	cout<<endl;
	strcpy(buff,msg1);
	strcat(buff,msg2);
    for (j = 1; j<=64; j++)
	{
		//buff=new char[strlen(strcat(msg1,msg2))];
        amsg[j] = buff[j-1];
        cout<<amsg[j];
    }
    cout<<endl;
    //read array of random numbers
	ifstream fin;
	fin.open("d:\\vc常用数值算法集\\data\\tarray.dat",ios::in|ios::nocreate);
	if (!fin)
	{
		cerr<<"could not open d:\\vc常用数值算法集\\data\\tarray.dat"<<endl;
		exit(1);
	}
	for (i=1; i<=nlen; i++)
	{
		fin>>a[i];
	}
	fin.close();
    //create array b and array c
    for (i = 1; i<=nlen; i++)
	{
        b[i] = i;
        c[i] = nlen + 1 - i;
    }
    //sort array a while mixing b and c
    sort3(nlen, a, b, c, wksp, indx);
    //scramble message according to array b
    for (i = 1; i<=nlen; i++)
	{
        j = (int)b[i];
        bmsg[i] = amsg[j];
    }
    cout<<endl;
    cout<<"Scrambled message:"<<endl;
	cout<<endl;
    for (j = 1; j<=nlen; j++)
	{
       cout<<bmsg[j];
    }
    cout<<endl;
    //unscramble according to array c
    for (i = 1; i<=nlen; i++)
	{
        j = (int)c[i];
        cmsg[j] = bmsg[i];
    }
    cout<<endl;
    cout<<"Mirrored message:"<<endl;
	cout<<endl;
    for (j = 1; j<=nlen; j++)
	{
       cout<<cmsg[j];
    }
	cout<<endl;
}