Go: package main

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

func main() {
	io := NewIo()
	defer io.Flush()
	n := io.NextInt()
	for i := 0; i < n; i++ {
		s, t := io.NextLine(), io.NextLine()
		io.Println(f(s, t))
	}
}

func f(s, t string) string {
	for i := len(s) - 1; i >= 0; i-- {
		switch s[i] {
		case 'C':
			t = strings.Join([]string{t[1:], string(t[0])}, "")
		case 'J':
			t = strings.Join([]string{string(t[len(t)-1]), t[:len(t)-1]}, "")
		case 'E':
			if len(t)%2 == 1 {
				t = strings.Join([]string{t[len(t)/2+1:], string(t[len(t)/2]), t[:len(t)/2]}, "")
			} else {
				t = strings.Join([]string{t[len(t)/2:], t[:len(t)/2]}, "")
			}
		case 'A':
			r := []rune(t)
			for i, n := 0, len(r); i < n/2; i++ {
				r[i], r[n-i-1] = r[n-i-1], r[i]
			}
			t = string(r)
		case 'M':
			r := []rune(t)
			for i := 0; i < len(r); i++ {
				if '0' <= r[i] && r[i] < '9' {
					r[i]++
				} else if r[i] == '9' {
					r[i] = '0'
				}
			}
			t = string(r)
		case 'P':
			r := []rune(t)
			for i := 0; i < len(r); i++ {
				if '0' < r[i] && r[i] <= '9' {
					r[i]--
				} else if r[i] == '0' {
					r[i] = '9'
				}
			}
			t = string(r)
		}
	}
	return t
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := make([]interface{}, 0, len(a))
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := make([]interface{}, 0, len(a))
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: #include <bits/stdc++.h>

using namespace std;

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = long long;
using P = std::tuple<int,int>;

const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);
    
    int N;
    std::cin >> N;

    for(int i=0;i<N;++i){
        string order;
        std::cin >> order;

        reverse(order.begin(), order.end());
    
        string message;
        std::cin >> message;

        for(const char& c : order){
            if(c == 'J'){
                string newMessage = *message.rbegin() + message.substr(0, message.size() - 1);
                message = newMessage;
            }else if(c == 'C'){
                string newMessage = message.substr(1, message.size() - 1) + message[0];
                message = newMessage;            
            }else if(c == 'E'){
                int half = message.size() / 2;
                string left = message.substr(0, half),
                    right = message.substr(message.size() - half, half);
                if(message.size() % 2 == 0){
                    message = right + left;
                }else{
                    message = right + message[half] + left;
                }
            }else if(c == 'A'){
                reverse(message.begin(), message.end());
            }else if(c == 'P'){
                for(auto &c : message){
                    if(isdigit(c)){
                        c = '0' + (c - '0' + 10 - 1) % 10;
                    }
                }
            }else if(c == 'M'){
                for(auto &c : message){
                    if(isdigit(c)){
                        c = '0' + (c - '0' + 1) % 10;
                    }
                }
            }else{
                assert(false);
            }
        }

        std::cout << message << std::endl;
    }
}

C++: #include<iostream>
#include<string>
using namespace std;
int main(){
	int n;
	string a,b;
	char c[1000],d[1000];
	cin>>n;
	for(int u=0;u<n;u++){
		cin>>a>>b;
		for(int i=0;i<b.size();i++){
			d[i]=b[i];
			c[i]=d[i];
		}
		for(int i=a.size()-1;i>=0;i--){
			if(a[i]=='J'){
				for(int i=0;i<b.size()-1;i++)
					c[i+1]=d[i];
				c[0]=d[b.size()-1];
			}
			if(a[i]=='C'){
				for(int i=0;i<b.size()-1;i++)
					c[i]=d[i+1];
				c[b.size()-1]=d[0];
			}
			if(a[i]=='E'){
				for(int i=0;i<b.size();i++){
					if(i<b.size()/2)
						c[i+b.size()-b.size()/2]=d[i];
					else
						c[i-b.size()+b.size()/2]=d[i];
				}
			}
			if(a[i]=='A'){
				for(int i=0;i<b.size();i++)
					c[i]=d[b.size()-1-i];
			}
			if(a[i]=='P'){
				for(int i=0;i<b.size();i++){
					bool check=false;
					if(c[i]>='1'&&c[i]<='9'){
						c[i]=c[i]-1;
						check=true;
					}
					else if(c[i]=='0'){
						c[i]='9';
						check=true;
					}
					if(check==false)
						c[i]=d[i];
				}
			}
			if(a[i]=='M'){
				for(int i=0;i<b.size();i++){
					bool check=false;
					if(c[i]>='0'&&c[i]<='8'){
						c[i]=c[i]+1;
						check=true;
					}
					else if(c[i]=='9'){
						c[i]='0';
						check=true;
					}
					if(check==false)
						c[i]=d[i];
				}
			}
			for(int i=0;i<b.size();i++)
				d[i]=c[i];
		}
		cout<<endl;
		for(int i=0;i<b.size();i++)
			cout<<d[i];
		cout<<endl;
	}
	return 0;
}

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

int main(){
  int n;
  cin>>n;
  for(int i=0;i<n;i++){
    char a[7],ans[26],b[26],x=0,y=0;
    scanf("%s",a);
    x=strlen(a);
    scanf("%s",ans);
    y=strlen(ans);  
    for(int i=0;i<y;i++)
      cout<<ans[i]<<endl<<endl;

    for(int k=0;k<x;k++){

      if(a[k]=='J'){//??????
	b[y-1]=ans[0];
	for(int j=1;j<y;j++) b[j-1]=ans[j];
      }
      else if(a[k]=='C'){//??????
	b[0]=ans[y-1];
	for(int j=0;j<y-1;j++) b[j+1]=ans[j];
      }
      else if(a[k]=='E'){//swap
	if(y%2==0)
	  for(int j=0;j<y/2;j++) 
	    swap(ans[j],ans[j+(y/2)]);
	else
	  for(int j=0;j<y/2;j++) 
	    swap(ans[j],ans[j+(y/2)+1]);

	for(int j=0;j<y;j++)
	  b[j]=ans[j];

      }
      else if(a[k]=='A'){//????????????
	int o=y;
	while(1){
	  if(o==0)break;
	  for(int j=0;j<y;j++){
	    b[j]=ans[o-1];
	    o--;
	  }
	}
      }
      else if(a[k]=='P'){//+1
	for(int j=0;j<y;j++) 
	  if(ans[j]>='0'&&ans[j]<='8') b[j]=ans[j]+1;
	  else if(ans[j]=='9') b[j]=ans[j]-9;
    }
      else if(a[k]=='M')//-1
	for(int j=0;j<y;j++) 
	  if(ans[j]>='1'&&ans[j]<='9') b[j]=ans[j]-1;
	  else if(ans[j]=='0') b[j]=ans[j]+9;

      for(int j=0;j<y;j++)
	ans[j]=b[j];
    }
      for(int j=0;j<y;j++)
	cout<<ans[j];
      cout<<endl;
    
  }
  return 0;
}