#include<iostream> #include<cstring> using namespace std; class EV{ public: EV(const int &vR, const int& vN) { result = vR; n =vN; } EV(){} int getResult() const { return result; } int getN() const { return n; } void setResult(const int& r) { result = r; } void setN(const int& N) { n = N; } private: int result, n ; }; EV evaluate(const char* x) { EV ev(0,0); EV v1, v2; if(*x == 0) return ev; if(x[0] >= '0' && x[0] <= '9') { ev.setResult(x[0] - '0') ; ev.setN(1); return ev; } v1 = evaluate(x + 1); v2 = evaluate(x + 1 + v1.getN()); if(x[0] == '+') ev.setResult(v1.getResult() + v2.getResult()); if(x[0] == '*') ev.setResult(v1.getResult() * v2.getResult()); if(x[0] == '-') ev.setResult(v1.getResult() - v2.getResult()); ev.setN( 1 + v1.getN() + v2.getN()); return ev; } int main(int argc, char* argv[]) { string s = "-+3*5+261"; const EV &ev = evaluate((char*)(s.c_str())); int res = ev.getResult(); cout << res << endl; return 0; }