#define TRUE 1#define FALSE 0#define STACK_SIZE 50   /*stack at most 50 elem*/#define STACK_ELEMENT_TYPE char        /* Needs to change type for different program !*/typedef struct {        STACK_ELEMENT_TYPE elem[STACK_SIZE];        int top;}seqstack;void Initstack(seqstack *S){     S->top=-1;}int Push(seqstack *S, STACK_ELEMENT_TYPE x){    if (S->top==STACK_SIZE)        return(FALSE);      /*stack is full*/    S->top++;    S->elem[S->top] = x;    return (TRUE);}int Pop(seqstack *S,STACK_ELEMENT_TYPE *x){    if(S->top==-1)       return(FALSE);   /*stack is empty*/    *x=S->elem[S->top];    S->top--;    return (TRUE);}int Gettop(seqstack *S, STACK_ELEMENT_TYPE *x){    if(S->top==-1)       printf("There is no element!\n");    *x=S->elem[S->top];    return (TRUE);}