Go: package main

import (
	"bufio"
	"os"
	"strings"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

func cipher(text string, direction int, int_shift int) string {
	shift, offset := rune(int_shift), rune(26)
	runes := []rune(text)
	for index, char := range runes {
		switch direction {
		case 1:
			if char >= 'a' && char <= 'z'-shift || char >= 'A' && char <= 'Z'-shift {
				char = char + shift
			} else if char > 'z'-shift && char <= 'z' || char > 'Z'-shift && char <= 'Z' {
				char = char + shift - offset
			}
		case -1:
			if char >= 'a'+shift && char <= 'z' || char >= 'A'+shift && char <= 'Z' {
				char = char - shift
			} else if char >= 'a' && char < 'a'+shift || char >= 'A' && char < 'A'+shift {
				char = char - shift + offset
			}
		}
		runes[index] = char
	}
	return string(runes)
}

func main() {
	for scanner.Scan() {
		infos := strings.Split(scanner.Text(), " ")
		plain := make([]string, len(infos))
		// fmt.Println(infos)
		Decryption:
			for i := 0; i < 26; i++ {
				for j := range infos {
					plain[j] = cipher(infos[j], 1, i)
				}
				for j := range plain {
					if plain[j] == "this" || plain[j] == "that" || plain[j] == "the" {
						break Decryption
					}
				}
			}
			fmt.Println(strings.Join(plain, " "))
	}
}

C++: #include <iostream>
#include <string>
#include <cctype>
using namespace std;

int main() {
  string s;
  while(getline(cin, s)) {
    for (int i=0; i<25; i++) {
      string s2(s);
      for (int j=0; j<s.length(); j++) {
        if (isalpha(s[j]))
          s2[j] = (s[j]-'a'+i) % 26 + 'a';
      }
      if (s2.find("the")!=-1||s2.find("this")!=-1||s2.find("that")!=-1) {
        cout << s2 << endl;
        break;
      }
    }
  }
}

C++: #include <iostream>
#include <string>
using namespace std;
int main(){
	string a;
	while(getline(cin,a)){
	int k=0;
	int check=0;
	while(true){
		if(k>52)
			break;
		for(int j=0;j<a.size();j++){
			if(isalpha(a[j])!=0)
				if(a[j]=='z')
					a[j]='a';
				else
				    a[j]++;
		}
		for(int i=0;i<a.size()-2;i++){
			if(a[i]=='t'&&a[i+1]=='h'&&a[i+2]=='e'&&check==0){
				for(int i=0;i<a.size();i++)
		            cout<<a[i];
	            cout<<endl;
				check=1;
			}
			if(a[i]=='t'&&a[i+1]=='h'&&a[i+2]=='i'&&a[i+3]=='s'&&check==0){
				for(int i=0;i<a.size();i++)
		            cout<<a[i];
	            cout<<endl;
				check=1;
			}
			if(a[i]=='t'&&a[i+1]=='h'&&a[i+2]=='a'&&a[i+3]=='t'&&check==0){
				for(int i=0;i<a.size();i++)
		            cout<<a[i];
	            cout<<endl;
				check=1;
			}
		}
		k++;
	}
	}
	return 0;
}

C++: #include <iostream>
#include <string>

using namespace std;

string rot(string);

int main(void){
	string str;

	while(getline(cin,str)){
		while(str.find("the")==string::npos && str.find("that")==string::npos && str.find("this")==string::npos)
			str=rot(str);
		cout << str << endl;
	}
}

string rot(string str){
	for(int i=0;i<str.size();i++)
		if(str[i]>='a'&&str[i]<='z')
			str[i]=str[i]=='z'?'a':str[i]+1;

	return str;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;

int main(){
	char input[81],str[50][81];
	const char cmp[3][5]={"that","this","the"};
	int pos=0,last_pos=0,i,j,k,diff,n;
	bool flag;

	while(fgets(input,81,stdin)!=NULL){;
		last_pos=0;
		pos=0;
		for(i=0;input[i]!='\0';i++){
			if(input[i]==' ' || input[i]=='.' || input[i]=='\n'){
				for(j=last_pos;j<i;j++){
					str[pos][j-last_pos]=input[j];
				}
				str[pos][j-last_pos]='\0';
				pos++;
				last_pos=i+1;
			}
		}

		n=0;
		flag=false;
		while(++n){
			for(i=0;i<pos;i++){
				for(j=0;str[i][j]!='\0';j++){
					str[i][j]+=1;
					if('a'>str[i][j]){
						str[i][j]+='z'-'a'+1;
					}else if('z'<str[i][j]){
						str[i][j]+='a'-'z'-1;
					}
				}
			}

			for(i=0;i<pos;i++){
				for(j=0;j<3;j++){
					if(strcmp(str[i],cmp[j])==0){
						flag=true;
                        j=3;i=pos;
					}
				}
			}
			if(flag) break;
		}

		int temp;
		for(i=0;input[i]!='\n';i++){
			if(input[i]!='.' && input[i]!=' '){
				temp=input[i]+n;
				if('a'>temp){
					input[i]=temp+'z'-'a'+1;
				}else if('z'<temp){
					input[i]=temp+'a'-'z'-1;
				}
			}
		}
		printf("%s",input);
	}

	return 0;
}

C++: #include <iostream>
#include <iomanip>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>
#include <sstream>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <numeric>
#include <cmath>
#include <climits>
#include <limits>
#include <cfloat>
#include <fstream>
using namespace std;

int main()
{
	const string key[] = { "the", "this", "that" };
//	cut here before submit 
//	freopen("testcase.cc", "r", stdin);
	string str = "";
	
	while (getline (cin, str )){
		int len = str.length();
		int i,j;
		vector <bool> match (3, false);
		for (j = 0; j < 26; ++j){
			string curr = str;
			for (i = 0; i < len; ++i){
				if ( isalpha(curr[i]) ){
					curr[i] = (curr[i] - 'a' + j) % 26 + 'a';
				} // end if
			} // end for
			for (i = 0; i < 3; ++i){
				if ( curr.find(key[i]) != string::npos ){
					match[i] = true;
				} // end if
			} // end for
			if ((int)count(match.begin(), match.end(), true ) == 3){
				cout << curr << endl;
				break;
			} // end if
		} // end for
	} // end while
		
	return 0;
}

C++: #include<iostream>
#include<string>
int main(){
	std::string str;
	while(std::getline(std::cin,str)){
	for(int i=0;i<str.size();i++){
		if(str[i]!=' '&&str[i]!='z')str[i]+=1;
		if(str[i]=='z')str[i]-=25;
	}
	std::cout<<str<<std::endl;
	}
	return 0;
}

C++: #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#pragma warning(disable:4996)

bool Check(char* Str);

int main()
{

	int  nCnt = 0;
	char PhraseIn[80];
	char PhraseOut[80] = "\0";
	int  nSlide = 1;

	gets(PhraseIn);

	while (1)
	{
		for (nCnt = 0; PhraseIn[nCnt] != '\0'; nCnt++)
		{
			if (PhraseIn[nCnt] == ' ' || PhraseIn[nCnt] == '.' || PhraseIn[nCnt] == '\n')
			{
				PhraseOut[nCnt] = PhraseIn[nCnt];
				continue;
			}

			PhraseOut[nCnt] = PhraseIn[nCnt] - nSlide;

			if (PhraseOut[nCnt] > 122)
				PhraseOut[nCnt] = 97 + (nSlide-1);

			if (PhraseOut[nCnt] < 97)
				PhraseOut[nCnt] = 122 - (nSlide - 1);
		}

		if (Check(PhraseOut))
			break;
		else
			nSlide++;
	}

	printf("%s", PhraseOut);

	return 0;
}

bool Check(char* Str)
{
	int nCnt = 0;
	int nCnt2 = 0;

	while (Str[nCnt] != '\0')
	{
		char Work[10] = "\0";
		nCnt2 = 0;
		while (1)
		{
			if (Str[nCnt] == ' ' || Str[nCnt] == '.' || Str[nCnt] == '\n' || Str[nCnt] == '\0')
			{
				nCnt++;
				break;
			}

			Work[nCnt2] = Str[nCnt];
			nCnt++;
			nCnt2++;
		}

		if (strcmp(Work, "this") == 0 || strcmp(Work, "the") == 0 || strcmp(Work, "that") == 0)
			return true;
	}

	return false;
}

C++: #include<iostream>
#include<stdio.h>
#include<string.h>
#include<ctype.h>

int main()
{
	char str[81];
	
	fgets( str, 80, stdin );
	
	while( 1 ){
		for( int i = 0; i < strlen( str ); i++ ){
			if( isalpha( str[i] ) ) str[i]++;
			
			if( str[i] > 'z' ){
			 	str[i] = 'a';
			}
		}
		
		if( strstr( str, "the" ) != NULL || strstr( str, "this" ) != NULL || strstr( str, "that" ) != NULL ) break;
	}
	
	std::cout << str << std::endl;

 	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<string>
using namespace std;
int main(){
  string s;
  int pl=0;
  getline(cin,s);
  for(int i =-27;i<27;i++){
    for(int j = 0; j < s.size(); j++){
      if(s[j]+i=='t' &&s[j+1]+i == 'h' && s[j+2]+i == 'e'){
	pl = i;
	break;
      }
      if(s[j]+i=='t' &&s[j+1]+i == 'h' && s[j+2]+i == 'a' && s[j+3]+i=='t'){
	pl = i;
	break;
      }
      if(s[j]+i=='t' &&s[j+1]+i == 'h' && s[j+2]+i == 'i' && s[j+3]+i=='s'){
	pl = i;
	break;
      }
    }
    if(pl!=0) break;
  }
  for(int i=0;i <s.size();i++){
    if(s[i]<='z' && s[i]>='a') s[i] += pl;
  }
  cout<<s<<endl;
}