Exemple pr siruri de char

#include <iostream>
#include <cstring>
using namespace std;

int main() {
    char ch,*p, a[100]="crocodil", b[100]="hipopotam", dr[100]={}, st[100]={};
    int nr=0,x, cif;

    if((ch>='a' && ch<='z')||(ch>='A' && ch<='Z'))  ///isalpha
    /*
    ///Transforma un int  --> sir de caractere
    strcpy(a,"");

    cin>>x;
    if(x==0){
        a[0]='0';
        a[1]='\0';
    }
    while(x!=0){
        cif=x%10;
        x=x/10;
        st[0]=cif+'0';
        st[1]='\0';
        strcpy(dr,a);
        strcat(st,dr);
        strcpy(a,st);
    }
    cout<<a;
    /*

    cin.getline(a,100);
    cin.getline(b,100);


    ////Trece Mishu la Sport? da/nu
    p=strtok(a," ,.");
    while(p!=NULL){
        if(p[0]>='0' && p[0]<='9'){
            for(int i=0;i<strlen(p);i++){
                nr=nr*10+p[i]-'0';
            }
        }
        p=strtok(NULL," .");
    }
    if(nr>=50){
        cout<<"Da";
    }
    else{
        cout<<"Nu";
    }



   ///abCd ---> ABCD
    for(int i=0;i<strlen(a);i++){
        if(a[i]>='a' && a[i]<='z'){ ///isalpha(a[i])
            a[i]=a[i]-('a'-'A');
        }
    }
    cout<<a;
    /*


    ///Sa se copieze in sirul a primele 4 caractere din b
    p=strstr(a,b); ///p = a + poz
    if(p!=NULL){
        cout<<"ultima aparitie este pe poz:"<<p-a<<endl;
        cout<<p;
    }
    else{
        cout<<"nu exista";
    }
    //cout<<endl<<"abc";
    */
    return 0;
}