c++ program

#include <iostream> #include <cstdio> #include <sstream> #include <algorithm> #include <string> #include <stack> using namespace std; int PostfixOperation(string elements); int Ope(char ope, int ope1, int ope2); bool Operator(char x); bool Numvalue(char w); int main(){ while(1){ int choice; yy: cout << " "<<endl; cout << " "<<endl; cout<<" compilation of machine problems"<<endl; cout << " "<<endl; cout << "1. Operation Elements using Arrays"<<endl; cout << "2. Postfix Evaluator"<<endl; cout << "3. Hammer's Query"<<endl; cout << "4. Binary Search Trees"<<endl; cout << "5. Bubble Sort"<<endl; cout << "6. Selection Sort"<<endl; cout << "7. Insertion Sort"<<endl; cout << "Enter your choice: "; cin >> choice; cout<<" "<<endl; if(choice==1){ cout<<" Operation Elements using Arrays "<<endl; string word[100],a[50]; int num,numelem; xx: cout<<endl; cout<<"[1] add elements"<<endl; cout<<"[2] Modify elements"<<endl; cout<<"[3] Delete elements"<<endl; cout<<"[4] Display elements"<<endl; cout<<"[5] Count elements"<<endl; cout<<"[6] exit"<<endl; cin>>num; cout<<endl; if(num==1){ cout<<"[1] add elements"<<endl; cout<<"enter number of elements: "; cin>>numelem; for(int x=0;x<numelem;x++){ cin>>word[x]; } cout<<"<Back to main menu>"<<endl; goto xx; } if(num==2){ int pos; cout<<"Please enter position: "<<endl; cin>>pos; a[50]=word[pos]; cout<<"enter string: "; cin>>word[pos]; cout<<"modified "<< a[50] <<" to "<<word[pos]; goto xx; } if(num==3){ int pos; string a[90]; cout<<"Please enter position: "<<endl; cin>>pos; a[90] = word[pos]; word[pos]= " "; cout<< a[90]<<" is deleted "<<word[pos]; goto xx; } if(num==4){ int a; string v; for(int x=numelem;x>=0;x--){ cout<<word[x]<<" "; } goto xx; } if(num==5){ int a; a = numelem; for(int x=0;x<numelem;x++){ if(word[x]==" "){ a--; } } cout<<"there are "<< a << " elements"; goto xx; } if(num==6){ goto yy; } } else if(choice==2){ string elements; cout<<"Enter elements: "<<endl; getline(cin,elements); int Output = PostfixOperation(elements); cout<<"Output = "<<Output<<endl; } } } int PostfixOperation(string elements){ stack<int> mystack; for(int i = 0;i< elements.length();i++) { if(elements[i]==' '||elements[i]==',') { continue; } else if(Operator(elements[i])) { int ope2 = mystack.top(); mystack.pop(); int ope1 = mystack.top(); mystack.pop(); int result = Ope(elements[i], ope1, ope2); mystack.push(result); } else if(Numvalue(elements[i])){ int ope = 0; while(i<elements.length() && Numvalue(elements[i])) { ope = (ope*10) + (elements[i] - '0'); i++; } i--; mystack.push(ope); } } return mystack.top(); } bool Numvalue(char w) { if(w >= '0' && w <= '9') return true; return false; } bool Operator(char x) { if(x =='+'|| x =='*') return true; return false; } int Ope(char ope, int ope1, int ope2) { if(ope == '+') return ope1 + ope2; else if(ope == '*') return ope1 * ope2; else cout<<"Invalid "<<endl; return 0; }