凯撒密码程序Word版

#include

#include

char JFjiami(char ch,int n)

{

while(ch>='A'&&ch<='Z')

{

n=n%26;

return ('A'+(ch-'A'+n)%26); }

while(ch>='a'&&ch<='z')

{

n=n%26;

return ('a'+(ch-'a'+n)%26); }

while(ch>='0'&&ch<='9')

{

n=n%10;

return ('0'+(ch-'0'+n)%10); }

return ch;

}

char JFjiemi(char ch,int n)

{

static int k;

while(ch>='A'&&ch<='Z')

{ k=n%26;

n=26-k;

return ('A'+(ch-'A'+n)%26); }

while(ch>='a'&&ch<='z')

{ k=n%26;

n=26-k;

return ('a'+(ch-'a'+n)%26); }

while(ch>='0'&&ch<='9')

{ k=n%10;

n=10-k;

return ('0'+(ch-'0'+n)%10); }

return ch;

}

char CFjiami(char ch,int n)

{

if(n%2==0) n=n%10+1;

else n=n%10;

if(n%5==0) n=n+2;

else n=n;

while(ch>='A'&&ch<='Z')

{

return ('A'+((ch-'A')*n)%26); }

while(ch>='a'&&ch<='z')

{

return ('a'+((ch-'a')*n)%26); }

while(ch>='0'&&ch<='9')

{

return ('0'+((ch-'0')*n)%10); }

return ch;

}

char CFjiemi(char ch,int n)

{

int i;

int k,h;

if(n%2==0) n=n%10+1;

else n=n%10;

if(n%5==0) n=n+2;

else n=n;

while(ch>='A'&&ch<='Z')

{

for(i=0;i<100;i++)

{

k=((ch-'A')+i*26)%n;

if(k==0)

h=((ch-'A')+i*26)/n;

if(h>=0&&h<=26)

return ('A'+h);

}

}

while(ch>='a'&&ch<='z')

{

for(i=0;i

{

k=((ch-'a')+i*26)%n;

if(k==0)

h=((ch-'a')+i*26)/n;

if(h>=0&&h<=26)

return ('a'+h);

}

}

while(ch>='0'&&ch<='9')

{

for(i=0;i

{

k=((ch-'0')+i*10)%n;

if(k==0)

h=((ch-'0')+i*10)/n;

if(h>=0&&h<=9)

return ('0'+h);

}

}

return ch;

}

void menu()

{

printf("\n========================================================="); printf("\n 1.JFjiami the file");

printf("\n 2.CFljiami the file");

printf("\n 3.JFjiemi the file");

printf("\n 4.CFjiemi the file");

printf("\n 5.Quit\n");

printf("=========================================================\n"); printf("Please input a number rang from 1 to 5 and select a item:"); return;

}

void main()

{

int i,n;

char ch0,ch1;

FILE *in,*out;

char infile[20],outfile[20];

sleep(3);

menu();

ch0=getch();

while(ch0!='5')

{

if(ch0=='1')

{

clrscr();

printf("\nPlease input the infile:"); scanf("%s",infile);

if((in=fopen(infile,"r"))==NULL)

{

printf("Can not open the infile!\n"); printf("Press any key to exit!\n");

getch();

exit(0);

}

printf("Please input the key:");

scanf("%d",&n);

printf("Please input the outfile:");

scanf("%s",outfile);

if((out=fopen(outfile,"w"))==NULL)

{

printf("Can not open the outfile!\n"); printf("Press any key to exit!\n");

fclose(in);

getch();

exit(0);

}

while(!feof(in))

{

fputc(JFjiami(fgetc(in),n),out);

}

printf("\nJFjiami is over!\n");

fclose(in);

fclose(out);

sleep(1);

}

if(ch0=='2')

{

clrscr();

printf("\nPlease input the infile:"); scanf("%s",infile);

if((in=fopen(infile,"r"))==NULL)

{

printf("Can not open the infile!\n"); printf("Press any key to exit!\n");

getch();

exit(0);