Language: C++

#include <algorithm>
#include <cmath>
#include <climits>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <cassert>
#include <functional>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
//#define LOG(...)
#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);++i)
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
#define RSORT(c) sort((c).rbegin(),(c).rend())
#define CLR(a) memset((a), 0 ,sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

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

struct UnionFind {
	vector<int> v;
	UnionFind(int n) : v(n)  { for (int i = 0; i < n; i++) v[i] = i; }
	int  find(int x)         { return v[x] == x ? x : v[x] = find(v[x]); }
	void unite(int x, int y) { v[find(x)] = find(y); }
};
const int wa[3][3]{
	{0,1,2},
	{1,1,2},
	{2,2,2}
};
const int se[3][3]{
	{0,0,0},
	{0,1,1},
	{0,1,2}
};
int calc(string& s, int &idx);
int brac(string& s, int &idx);
int num(string& s, int &idx);
int calc(string& s, int &idx) {
	int val1 = brac(s, idx);
	while (s[idx] == '*' || s[idx] == '+') {
		idx++;
		if (s[idx - 1] == '+') {
			int val2 = brac(s, idx);
			val1 = wa[val1][val2];
		}
		else {
			int val2 = brac(s, idx);
			val1 = se[val1][val2];
		}
	}
	return val1;
}
int brac(string& s, int &idx) {
	if (isdigit(s[idx])||s[idx]=='-')return number(s, idx);
	idx++;
	int val=calc(s, idx);
	idx++;
	return val;
}
int number(string& s, int &idx) {
	int not= 0;
	while (s[idx]=='-')
	{
		not++;
		idx++;
	}
	int val = s[idx] - '0';
	idx++;
	if (not% 2 == 1)
		if (val == 0)
			val = 2;
		else if (val == 2)
			val = 0;
	return val;
}
int main() {
	string s;
	while (cin >> s,s!=".") {
		int ans = 0;
		REP(i,3) {
			REP(j,3) {
				REP(k,3) {
					string s2 = s;
					replace(s2.begin(), s2.end(), 'P',(char)('0'+i) );
					replace(s2.begin(), s2.end(), 'Q', (char)('0' + j));
					replace(s2.begin(), s2.end(), 'R', (char)('0' + k));
					int num = 0;
					if (calc(s2,num) == 2)
						ans++;
				}
			}
		}
		cout <<ans<< endl;
	}
}

Compiler output:
a.cc: In function 'int brac(std::string&, int&)':
a.cc:81:49: error: 'number' was not declared in this scope
   81 |         if (isdigit(s[idx])||s[idx]=='-')return number(s, idx);
      |                                                 ^~~~~~
a.cc: In function 'int number(std::string&, int&)':
a.cc:88:13: error: expected unqualified-id before 'not' token
   88 |         int not= 0;
      |             ^~~
a.cc:91:22: error: expected primary-expression before ';' token
   91 |                 not++;
      |                      ^
a.cc:96:16: error: expected primary-expression before '%' token
   96 |         if (not% 2 == 1)
      |                ^