c2-1.c

/* code: c2-1.c   (v1.18.00) */
#include<stdio.h>
#include<stdlib.h>

#define MAX 128
#define PUSH_SUCCESS    1
#define PUSH_FAILURE   -1
#define POP_SUCCESS     2
#define POP_FAILURE    -2

/* ------------------------------------------- */
void stack_init (int *top) {
  *top = 0;
}

/* ------------------------------------------- */
void display (int stack[], int top) {
  int i;
  printf ("STACK(%d): ", top);
  for (i = 0; i < top; i++) {
    printf ("%d ", stack[i]);
  }
  printf ("\n");
}

/* ------------------------------------------- */
int push (int stack[], int *top, int data) {
  if (*top >= MAX) {
    /* stack overflow */
    return PUSH_FAILURE;
  }
  else {
    stack[*top] = data;
    (*top)++;
    return PUSH_SUCCESS;
  }
}

/* ------------------------------------------- */
int pop (int stack[], int *top, int *data) {
  if ((*top) > 0) {
    *data = stack[(*top) - 1];
    (*top)--;
    return POP_SUCCESS;
  }
  else {
    /* stack empty */
    return POP_FAILURE;
  }
}

/* ------------------------------------------- */
int main () {
  int stack[MAX];
  int top, data;

  stack_init (&top);
  data = 300;
  printf ("push: %d\n", data);
  push (stack, &top, data);
  data = 400;
  printf ("push: %d\n", data);
  push (stack, &top, data);
  data = 500;
  printf ("push: %d\n", data);
  push (stack, &top, data);
  display (stack, top);
  pop (stack, &top, &data);
  printf ("pop:  %d\n", data);
  pop (stack, &top, &data);
  printf ("pop:  %d\n", data);
  pop (stack, &top, &data);
  printf ("pop:  %d\n", data);
  return 0;
}

q2-1.c

/* code: q2-1.c   (v1.18.00) */
#include<stdio.h>
#include<stdlib.h>

#define MAX 128
#define PUSH_SUCCESS    1
#define PUSH_FAILURE   -1
#define POP_SUCCESS     2
#define POP_FAILURE    -2

/* ------------------------------------------- */
int peek (int stack[], int *top, int *data) {
  if ((*top) > 0) {
    *data = stack[(*top) - 1];
    return POP_SUCCESS;
  }
  else {
    /* stack empty */
    return POP_FAILURE;
  }
}

/* ------------------------------------------- */
void stack_init (int *top) {
  *top = 0;
}

/* ------------------------------------------- */
void display (int stack[], int top) {
  int i;
  printf ("STACK(%d): ", top);
  for (i = 0; i < top; i++) {
    printf ("%d ", stack[i]);
  }
  printf ("\n");
}

/* ------------------------------------------- */
int push (int stack[], int *top, int data) {
  if (*top >= MAX) {
    /* stack overflow */
    return PUSH_FAILURE;
  }
  else {
    stack[*top] = data;
    (*top)++;
    return PUSH_SUCCESS;
  }
}

/* ------------------------------------------- */
int pop (int stack[], int *top, int *data) {
  if ((*top) > 0) {
    *data = stack[(*top) - 1];
    (*top)--;
    return POP_SUCCESS;
  }
  else {
    /* stack empty */
    return POP_FAILURE;
  }
}

/* ------------------------------------------- */
int main () {
  int stack[MAX];
  int top, data;

  stack_init (&top);
  data = 300;
  printf ("push: %d\n", data);
  push (stack, &top, data);
  data = 400;
  printf ("push: %d\n", data);
  push (stack, &top, data);
  data = 500;
  printf ("push: %d\n", data);
  push (stack, &top, data);

  peek (stack, &top, &data);
  printf ("peek: %d\n", data);
  peek (stack, &top, &data);
  printf ("peek: %d\n", data);

  display (stack, top);

  pop (stack, &top, &data);
  printf ("pop:  %d\n", data);

  peek (stack, &top, &data);
  printf ("peek: %d\n", data);

  pop (stack, &top, &data);
  printf ("pop:  %d\n", data);
  pop (stack, &top, &data);
  printf ("pop:  %d\n", data);
  return 0;
}

q2-2.c

/* code: q2-2.c   (v1.18.00) */
#include<stdio.h>
#include<stdlib.h>
#include<string.h>

#define MAX 128
#define PUSH_SUCCESS    1
#define PUSH_FAILURE   -1
#define POP_SUCCESS     2
#define POP_FAILURE    -2

/* ------------------------------------------- */
void stack_init (int *top) {
  *top = 0;
}

/* ------------------------------------------- */
void display_char (int stack[], int top) {
  int i;
  printf ("STACK(%d): ", top);
  for (i = 0; i < top; i++) {
    printf ("%c", stack[i]);
  }
  printf ("\n");
}

/* ------------------------------------------- */
int push (int stack[], int *top, int data) {
  if (*top >= MAX) {
    /* stack overflow */
    return PUSH_FAILURE;
  }
  else {
    stack[*top] = data;
    (*top)++;
    return PUSH_SUCCESS;
  }
}

/* ------------------------------------------- */
int pop (int stack[], int *top, int *data) {
  if ((*top) > 0) {
    *data = stack[(*top) - 1];
    (*top)--;
    return POP_SUCCESS;
  }
  else {
    /* stack empty */
    return POP_FAILURE;
  }
}

/* ------------------------------------------- */
int main () {
  int stack[MAX];
  int top, data;
  int i, len;
  char str[128];

  sprintf (str, "%s", "The_Open_University_of_Japan");
  len = strlen (str);

  stack_init (&top);

  for (i = 0; i < len; i++) {
    data = str[i];
    push (stack, &top, data);
  }

  display_char (stack, top);

  for (i = 0; i < len; i++) {
    pop (stack, &top, &data);
    printf ("%c", data);
  }
  printf ("\n");

  return 0;
}

q2-3.c

/* code: q2-3.c   (v1.18.00) */
#include<stdio.h>
#include<stdlib.h>

#define DATA_SIZE   100000000
#define MAX         100000000

#define PUSH_SUCCESS    1
#define PUSH_FAILURE   -1
#define POP_SUCCESS     2
#define POP_FAILURE    -2

/* ------------------------------------------- */
void stack_init (int *top) {
  *top = 0;
}

/* ------------------------------------------- */
void display (int stack[], int top) {
  int i;
  printf ("STACK(%d): ", top);
  for (i = 0; i < top; i++) {
    printf ("%d ", stack[i]);
  }
  printf ("\n");
}

/* ------------------------------------------- */
int push (int stack[], int *top, int data) {
  if (*top >= MAX) {
    /* stack overflow */
    return PUSH_FAILURE;
  }
  else {
    stack[*top] = data;
    (*top)++;
    return PUSH_SUCCESS;
  }
}

/* ------------------------------------------- */
int pop (int stack[], int *top, int *data) {
  if ((*top) > 0) {
    *data = stack[(*top) - 1];
    (*top)--;
    return POP_SUCCESS;
  }
  else {
    /* stack empty */
    return POP_FAILURE;
  }
}




/* ------------------------------------------- */
int main () {
  int *stack;
  int top, data, i;

  stack = malloc (sizeof (int) * MAX);
  printf ("data size: %d\n", DATA_SIZE);
  stack_init (&top);

  printf ("push:\n");
  for (i = 0; i < DATA_SIZE; i++) {
    data = rand () % 1000;
    if (i >= DATA_SIZE - 5)
      printf ("%3d (index:%d)\n", data, top);
    push (stack, &top, data);
  }
  printf ("\n");

  printf ("pop:\n");
  for (i = 0; i < 5; i++) {
    pop (stack, &top, &data);
    printf ("%3d (index:%d)\n", data, top);
  }
  printf ("\n");

  free (stack);

  return 0;
}

q2-4.c

/* code: q2-4.c   (v1.18.00) */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define MAX           1024

#define PUSH_SUCCESS    1
#define PUSH_FAILURE   -1
#define POP_SUCCESS     2
#define POP_FAILURE    -2
/* ------------------------------------------- */
void stack_init (int *top) {
  *top = 0;
}


/* ------------------------------------------- */
int push (int stack[], int *top, int data) {
  if (*top >= MAX) {
    /* stack overflodelim */
    return PUSH_FAILURE;
  }
  else {
    stack[*top] = data;
    (*top)++;
    return PUSH_SUCCESS;
  }
}

/* ------------------------------------------- */
int pop (int stack[], int *top, int *data) {
  if ((*top) > 0) {
    *data = stack[(*top) - 1];
    (*top)--;
    return POP_SUCCESS;
  }
  else {
    /* stack empty */
    return POP_FAILURE;
  }
}

/* ------------------------------------------- */
int rpn (char *str) {
  int stack[MAX];
  int top, i;
  int a, b;
  char *endptr;
  char *delim = " \n\t\r\f";

  a = b = 0;
  stack_init (&top);

  for (str = strtok (str, delim); str; str = strtok (0, delim)) {
    a = (int) strtod (str, &endptr);
    if (endptr > str) {
      printf ("n: ");
      push (stack, &top, a);
    }
    else if (*str == '+') {
      printf ("%c: ", *str);
      pop (stack, &top, &b);
      pop (stack, &top, &a);
      push (stack, &top, (a + b));
    }
    else if (*str == '-') {
      printf ("%c: ", *str);
      pop (stack, &top, &b);
      pop (stack, &top, &a);
      push (stack, &top, (a - b));
    }
    else if (*str == '*') {
      printf ("%c: ", *str);
      pop (stack, &top, &b);
      pop (stack, &top, &a);
      push (stack, &top, (a * b));
    }
    else if (*str == '/') {
      printf ("%c: ", *str);
      pop (stack, &top, &b);
      pop (stack, &top, &a);
      push (stack, &top, (a / b));
    }
    else {
      fprintf (stderr, "[%c]: ", *str);
      fprintf (stderr, "unknown oeprators\n");
    }

    for (i = 0; i < top; i++) {
      printf (" %d", stack[i]);
    }
    printf ("\n");
  }

  if (top != 1) {
    fprintf (stderr, "stack error\n");
    exit (-1);
  }

  pop (stack, &top, &a);
  return a;
}


/* ------------------------------------------- */
int main () {
  int result;
  char rpn_str[] = " 3 6 + 1 2 + / ";

  printf ("RPN expression: %s\n\n", rpn_str);
  result = rpn (rpn_str);
  printf ("\n");
  printf ("result: %d\n", result);
  return 0;
}

q2-5.c

/* code: q2-5.c   (v1.18.00) */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define MAX           1024

#define PUSH_SUCCESS    1
#define PUSH_FAILURE   -1
#define POP_SUCCESS     2
#define POP_FAILURE    -2
/* ------------------------------------------- */
void stack_init (int *top) {
  *top = 0;
}


/* ------------------------------------------- */
int push (int stack[], int *top, int data) {
  if (*top >= MAX) {
    /* stack overflodelim */
    return PUSH_FAILURE;
  }
  else {
    stack[*top] = data;
    (*top)++;
    return PUSH_SUCCESS;
  }
}

/* ------------------------------------------- */
int pop (int stack[], int *top, int *data) {
  if ((*top) > 0) {
    *data = stack[(*top) - 1];
    (*top)--;
    return POP_SUCCESS;
  }
  else {
    /* stack empty */
    return POP_FAILURE;
  }
}

/* ------------------------------------------- */
int rpn (char *str) {
  int stack[MAX];
  int top, i;
  int a, b;
  char *endptr;
  char *delim = " \n\t\r\f";

  a = b = 0;
  stack_init (&top);

  for (str = strtok (str, delim); str; str = strtok (0, delim)) {
    a = (int) strtod (str, &endptr);
    if (endptr > str) {
      printf ("n: ");
      push (stack, &top, a);
    }
    else if (*str == '+') {
      printf ("%c: ", *str);
      pop (stack, &top, &b);
      pop (stack, &top, &a);
      push (stack, &top, (a + b));
    }
    else if (*str == '-') {
      printf ("%c: ", *str);
      pop (stack, &top, &b);
      pop (stack, &top, &a);
      push (stack, &top, (a - b));
    }
    else if (*str == '*') {
      printf ("%c: ", *str);
      pop (stack, &top, &b);
      pop (stack, &top, &a);
      push (stack, &top, (a * b));
    }
    else if (*str == '/') {
      printf ("%c: ", *str);
      pop (stack, &top, &b);
      pop (stack, &top, &a);
      push (stack, &top, (a / b));
    }
    else {
      fprintf (stderr, "[%c]: ", *str);
      fprintf (stderr, "unknown oeprators\n");
    }

    for (i = 0; i < top; i++) {
      printf (" %d", stack[i]);
    }
    printf ("\n");
  }

  if (top != 1) {
    fprintf (stderr, "stack error\n");
    exit (-1);
  }

  pop (stack, &top, &a);
  return a;
}


/* ------------------------------------------- */
int main () {
  int result;
  char rpn_str[] = " 5 1 2 + 4 * + 3 - ";

  //
  // 5 + ((1 + 2) * 4) - 3
  //

  printf ("RPN expression: %s\n\n", rpn_str);
  result = rpn (rpn_str);
  printf ("\n");
  printf ("result: %d\n", result);
  return 0;
}