栈的数组实现

//栈的数组实现//数组从1开始,栈S在S[]处存放栈顶位置#include <iostream>#include <cstring>#define N 1000using namespace std;int STACK_EMPTY(int S[]){    if(S[0]==0) return true;    else return false;}void PUSH(int S[],int x){    S[0]++;    S[S[0]]=x;}int POP(int S[]){    if(S[0]==0)    {        cout << "underflow" <<endl;        return 0;    }    else    {        S[0]--;        return S[S[0]+1];    }}int main(int argc, char *argv[]){    int S[N];    memset(S,0,sizeof(S));    PUSH(S,10);    PUSH(S,20);    int test=POP(S);    cout << test << endl;    cout << "Hello World!" << endl;    return 0;}