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<iostream>
#include<stdlib.h>
#include<string.h>
using namespace std;
int main()
{
	int n;
	cin >> n;
	for (int i = 0; i < n; i++)
	{
		char messengers[7];
		char message[26];
		cin >> messengers;
		cin >> message;
		int messengersNum = strlen(messengers);
		int messLen = strlen(message);
		for (int j = 0; j < messengersNum; j++)
		{
			char c = messengers[j];
			if (c == 'J')
			{
				char tmp = message[0];
				for (int k = 0; k + 1 < messLen; k++)
				{
					message[k] = message[k + 1];
				}
				message[messLen - 1] = tmp;
			}
			else if (c == 'C')
			{
				char tmp = message[messLen - 1];
				for (int k = messLen - 1; k - 1 >= 0; k--)
				{
					message[k] = message[k - 1];
				}
				message[0] = tmp;
			}
			else if (c == 'E')
			{
				if (messLen % 2 == 0)
				{
					int range = messLen / 2;
					for (int k = 0; k + range< messLen; k++)
					{
						char tmp = message[k];
						message[k] = message[k + range];
						message[k + range] = tmp;
					}
				}
				else
				{
					int range = messLen / 2 + 1;
					for (int k = 0; k  + range < messLen; k++)
					{
						char tmp = message[k];
						message[k] = message[k + range];
						message[k + range] = tmp;
					}
				}
			}
			else if (c == 'A')
			{
				for (int k = 0; k < messLen - k; k++)
				{
					char tmp = message[k];
					message[k] = message[messLen - 1 - k];
					message[messLen - 1 - k] = tmp;
				}
			}
			else if (c == 'P')
			{
				for (int k = 0; k< messLen; k++)
				{
					if (message[k] >= '0' && message[k] <= '9')
					{
						message[k]++;
						if (message[k] > '9')
						{
							message[k] = '0';
						}
					}
				}
			}
			else if (c == 'M')
			{
				for (int k = 0; k< messLen; k++)
				{
					if (message[k] >= '0' && message[k] <= '9')
					{
						message[k]--;
						if (message[k] < '0')
						{
							message[k] = '9';
						}
					}
				}
			}
		}

		cout << message << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <string>
#include <cstring>
using namespace std;
typedef long long int ll;

void solve(){
	string s,t; cin >> s >> t;
	reverse(s.begin(),s.end());
	int n=t.size();
	for(char c:s){
		if(c=='J'){
			t=t.substr(n-1,1)+t.substr(0,n-1);
		}
		if(c=='C'){
			t=t.substr(1,n-1)+t.substr(0,1);
		}
		if(c=='E'){
			t=t.substr(t.size()-t.size()/2)+t.substr(t.size()/2,t.size()%2)+t.substr(0,t.size()/2);
		}
		if(c=='A'){
			reverse(t.begin(),t.end());
		}
		if(c=='P'){
			for(int i=0;i<n;i++){
				if('0'<=t[i]&&t[i]<='9'){
					if(t[i]=='0')t[i]+=9;
					else t[i]--;
				}
			}
		}
		if(c=='M'){
			for(int i=0;i<n;i++){
				if('0'<=t[i]&&t[i]<='9'){
					if(t[i]=='9')t[i]-=9;
					else t[i]++;
				}
			}
		}
	}
	cout << t << endl;
}

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	int q; cin >> q;
	while(q--){
		solve();
	}
}

C++: #include <iostream>
#include <string>
using namespace std;
int main() {
  int n, l, m;
  string s, t;
  char u, p;
  cin >> n;
  for (int i = 0; i < n; ++i) {
    cin >> s;
    cin >> t;
    l = s.size();
    m = t.size();
    for (int i = l-1; i >= 0; --i) {
      p = s[i];
      if (p == 'P') {
	for (int j = 0; j < m; ++j) {
	  if (t[j] == '0') t[j] = '9';
	  else if ('0' < t[j] && t[j] <= '9') {
	    t[j] = t[j] - 1;
	  }
	}
      } else if (p == 'M') {
	for (int j = 0; j < m; ++j) {
	  if (t[j] == '9') t[j] = '0';
	  else if ('0' <= t[j] && t[j] < '9') {
	    t[j] = t[j] + 1;
	  }
	}
      } else if (p == 'C') {
	u = t[0];
	for (int j = 0; j < m-1; ++j) t[j] = t[j+1];
	t[m-1] = u;
      } else if (p == 'A') {
	for (int j = 0; j < m/2; ++j) {
	  u = t[m-1-j];
	  t[m-1-j] = t[j];
	  t[j] = u;
	}
      } else if (p == 'E') {
	for (int j = 0; j < m/2; ++j) {
	  u = t[m/2+m%2+j];
	  t[m/2+m%2+j] = t[j];
	  t[j] = u;
	}
      } else if (p == 'J') {
	u = t[m-1];
	for (int j = m-1; j > 0; --j) t[j] = t[j-1];
	t[0] = u;
      }
      //      cout << p << " " << t << endl;
    }
    cout << t << endl;
  }
  return 0;
}

C++: #include <stdio.h>
#include <string.h>
int main() {
    int N,i,j,k,q;char T[50],c[9];scanf("%d",&N);while (N--) {
        scanf("%s%s",&c,&T);j=strlen(c),k=strlen(T)-1;
        while (j--) {
            if (c[j]=='P') {
                for (i=k;i>=0;i--) if (T[i]>='1' && T[i]<='9') T[i]--; else if (T[i]=='0') T[i]='9';}
            } else if (c[j]=='M') {
                for (i=k;i>=0;i--) if (T[i]>='0' && T[i]<='8') T[i]++; else if (T[i]=='9') T[i]='0';}
            } else if (c[j]=='E') {
                for (i=k,q=(k-1)/2;q>=0;i--,q--) swap(T[i],T[q]);
            } else if (c[j]=='A') {
                for (i=0,q=k;i<q;i++,q--) swap(T[i],T[q]);
            } else if (c[j]=='J') {
                c[8]=T[k];for (i=k;i>0;i--) T[i]=T[i-1];T[0]=c[8];
            } else {
                c[8]=T[0];for (i=0;i<k;i++) T[i]=T[i+1];T[k]=c[8];
            }
        }
        puts(T);
    }
}