古典密码学(替换置换加密)c程序

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1、替换：#includeintencrypt(){charSTR[27]={'X','N','Y','A','H','P','O','G','Z','Q','W','B','T','S','F','L','R','C','V','M','U','E','K','J','D','I'};charstr[27]={'d','l','r','y','v','o','h','e','z','x','w','p','t','b','g','f','j','q','n','m','u','s

2、','k','a','c','i'};intx,i=0;charcode[80],string[80];printf("请输入你的明文(80字符内的小写字符串)：");scanf("%s",string);printf("Thecodeis:");for(i=0;string[i];i++){x=string[i]-97;code[i]=STR[x];printf("%c",STR[x]);}printf("");return0;}intdecrypt(){charSTR[27]={'X',

3、'N','Y','A','H','P','O','G','Z','Q','W','B','T','S','F','L','R','C','V','M','U','E','K','J','D','I'};charstr[27]={'d','l','r','y','v','o','h','e','z','x','w','p','t','b','g','f','j','q','n','m','u','s','k','a','c','i'};intx,i=0;chardecode[80],STRING[

4、80];printf("请输入你的密文(80字符内的大写字符串)：");scanf("%s",STRING);printf("Thedecodeis:");for(i=0;STRING[i];i++){x=STRING[i]-65;decode[i]=str[x];printf("%c",str[x]);}printf("");return0;}intmain(){charSTR[27]={'X','N','Y','A','H','P','O','G','Z','Q','W','B','T'

5、,'S','F','L','R','C','V','M','U','E','K','J','D','I'};charstr[27]={'d','l','r','y','v','o','h','e','z','x','w','p','t','b','g','f','j','q','n','m','u','s','k','a','c','i'};intt,x,y=0,i=0;charcode[80],string[80];chardecode[80],STRING[80];printf("加密请输入

6、1，解密请输入0:");scanf("%d",&t);printf("");if(t==1){encrypt();for(i=0;code[i];i++){x=code[i]-65;decode[i]=str[x];if(decode[i]==string[i])y++;elsey=y;}if(y==i-1)printf("CRYPT_OK!");elseprintf("CRYPT_ERROR!");}elseif(t==0){decrypt();for(i=0;decode[i];

7、i++){x=decode[i]-65;code[i]=STR[x];if(code[i]==STRING[i])y++;elsey=y;}if(y==i-125)printf("CRYPT_OK!");elseprintf("CRYPT_ERROR!");}elseprintf("ERROR!");return0;}置换：#include#include#includechar*encrypt(char*str,intn){

8、inti,j,k,l,d;char*c,*s1,*c1;l=strlen(str);if((d=l%n)!=0)l=l+n-d;if((s1=(char*)malloc(l*sizeof(char)+1))==NULL){printf("Memoryerror!");exit(l);}if((c=(char*)malloc(l*sizeof(char)+1))==NULL){printf("Memoryerror!");exit(l);}c1=c;strcpy(s1,str);for(i