替代密码和置换密码的C语言实现

一、实验名称：二、实验目的：过程可表达为：E(m)=(m+k)modn其中，mnkE(m)为密解密算法是：m=D(L)=（L-k）mod加密：intencrypt(){{b[i]=a[i]-}{}return0;}解密：int{printf("{n[i]=(b[i]-return0;}451不变化明文字符，但是把字符在明文中的排列次序变化，来实现明文信息的加密。置加密：intjiami(){inti=0,j=0,key_len=0,text_len=0,row=0;charkey[LENGTH]={0};charnumber[LENGTH]={0};charptext[LENGTH*10]0charctext[LENGTH*10]0scanf("%s",ptext);i=while(ptext[i]!={}printf("输入密钥scanf("%s",key);i=0;while(key[i]!={}for(i=0;i<key_len;{number[i]=for(j=0;j<key_len;{if(key[j]<key[i])}}for(i=0;i<key_len;{for(j=i+1;j<key_len;{if(key[j]==key[i])}}if(text_len%key_len==0)row=text_len/key_len;row=text_len/key_len+for(i=0;i<key_len;{for(j=0;j<row;{ctext[i*row+j]=ptext[number[i]+}}for(i=0;i<key_len;{for(j=0;j<row;{printf("%c",ctext[i*row+}}return}解密：int{inti=0,j=0,key_len=0,text_len=0,row=0;charkey1[LENGTH]={0};charptext1[LENGTH*10]0charctext1[LENGTH*10]0charnumber1[LENGTH]={0};scanf("%s",ctext1);while(ctext1[i]!={}printf(scanf("%s",key1);i=0;while(key1[i]!={}for(i=0;i<key_len;{intj=0;number1[i]=0;for(j=0;j<key_len;{if(key1[j]<key1[i])}}for(i=0;i<key_len;{intj=for(j=i+1;j<key_len;{if(key1[j]==key1[i])}}if(text_len%key_len==0)row=text_len/key_len;row=text_len/key_len+for(i=0;i<key_len;{for(j=0;j<row;{ptext1[number1[i]+key_len*j]=ctext1[i*row+}}for(i=0;i<key_len;{for(j=0;j<row;{printf("%c",ptext1[i*row+}}return}45100个字母，那么对它的解密就会比较困难。#include<stdio.h>#include<conio.h>intk,i=0;chara[100];charint{{b[i]=a[i]-}{}return0;}int{{n[i]=(b[i]-return0;}int{intprintf("12\n");{}{}return}#include<stdio.h>#include<string.h>#defineLENGTH26intjiami(){inti=0,j=0,key_len=0,text_len=0,row=0;charkey[LENGTH]={0};charnumber[LENGTH]={0};charptext[LENGTH*10]0charctext[LENGTH*10]0scanf("%s",ptext);i=while(ptext[i]!={}printf("输入密钥scanf("%s",key);i=0;while(key[i]!={}for(i=0;i<key_len;{number[i]=for(j=0;j<key_len;{if(key[j]<key[i])}}for(i=0;i<key_len;{for(j=i+1;j<key_len;{if(key[j]==key[i])}}if(text_len%key_len==0)row=text_len/key_len;row=text_len/key_len+for(i=0;i<key_len;{for(j=0;j<row;{ctext[i*row+j]=ptext[number[i]+}}for(i=0;i<key_len;{for(j=0;j<row;{printf("%c",ctext[i*row+}}return}int{inti=0,j=0,key_len=0,text_len=0,row=0;charkey1[LENGTH]={0};charptext1[LENGTH*10]0charctext1[LENGTH*10]0charnumber1[LENGTH]={0};scanf("%s",ctext1);while(ctext1[i]!={}printf(scanf("%s",key1);i=0;while(key1[i]!={}for(i=0;i<key_len;{intj=0;number1[i]=0;for(j=0;j<key_len;{if(key1[j]<key1[i])}}for(i=0;i<key_len;{intj=for(j=i+1;j<key_len;{if(key1[j]==key1[i])}}if(text_len%key_len==0)row=text_len/key_len;row=text_len/key_len+for(i=0;i<key_len;{for(j=0;j<row;{ptext1[number1[i]+key_len*j]=ctex