hb.cpp

加密置换加密方法．能实现加解密的Ｃ程序．

#include<stdio.h>
#include<process.h>
void main()
{
	FILE*fp;
	int i,j,n,i1;
	char c[100],t,ch;
	char name1[100],name2[100],name3[200];
	printf("Input A filename:");
	scanf("%s",name1);

	if((fp=fopen(name1,"r"))==NULL)
	{
		printf("Can not open the file\n");
		exit(0);
	}
	printf("\n file A:\n");
	for (i=0;(ch=fgetc(fp))!=EOF;i++)
	{
		c[i]=ch;
		putchar(c[i]);
	}
	fclose(fp);
	i1=i;
printf("Input B filename:");
	scanf("%s",name2);
	if((fp=fopen(name2,"r"))==NULL)
	{printf("\n Can not open the file");
	exit(0);
	}
	printf("\n file B;\n");
	for (i =i1;(ch=fgetc(fp))!=EOF;i++)
	{
		c[i]=ch;
		putchar(c[i]);
	}
	fclose(fp);
	n=i;
	for(i=0;i<n;i++)
		for(j=i+1;j<n;j++)
			if(c[i]>c[j])
			{t=c[i];
			c[i]=c[j];
			c[j]=t;}
printf("Input C filename:");
	scanf("%s",name3);
printf("\n file C:\n");
fp=fopen(name3,"w");
for(i=0;i<n;i++)
{putc(c[i],fp);
putchar(c[i]);
}printf("\n");
fclose(fp);
}