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  1. #include <stdio.h>
  2. #include <stdlib.h>
  3.  
  4. struct stack {
  5. 	int v;
  6. 	struct stack *next;
  7. };
  8.  
  9. void init(struct stack **h)
  10. {
  11. 	*h = malloc(sizeof(struct stack));
  12. 	(*h)->next = NULL;
  13. }
  14.  
  15. void push(struct stack *h, int v)
  16. {
  17. 	struct stack *t;
  18.  
  19. 	t = malloc(sizeof(struct stack));
  20. 	t->v = v;
  21. 	t->next = h->next;
  22. 	h->next = t;
  23. }
  24.  
  25. int pop(struct stack *h)
  26. {
  27. 	int v;
  28. 	struct stack *t;
  29.  
  30. 	t = h->next;
  31. 	h->next = t->next;
  32. 	v = t->v;
  33. 	free(t);
  34.  
  35. 	return v;
  36. }
  37.  
  38. int stack_empty(struct stack *h)
  39. {
  40. 	return h->next == NULL;
  41. }
  42.  
  43. int main(void)
  44. {
  45. 	int op, n, c, op1, op2;
  46. 	struct stack *number, *operator;
  47. 	char s[200];
  48.  
  49. 	init(&number);
  50. 	init(&operator);
  51. 	while((c = getchar()) != '\n'){
  52. 		if(c <= '9' && c >= '0')
  53. 		{
  54. 			n = c-'0';
  55. 			while((c = getchar()) && c <= '9' && c >= '0')
  56. 			{
  57. 				n = n*10+c-'0';
  58. 			}
  59. 			push(number, n);
  60. 		}
  61. 		if(c == '\n' || c == EOF) break;
  62. 		if(c == '+' || c == '-' || c == '*')
  63. 		{
  64. 			push(operator, (int) c);
  65. 		} else if(c == ')')
  66. 		{
  67. 			op = pop(operator);
  68. 			if(op == '+'){
  69. 				n = pop(number)+pop(number);
  70. 				push(number, n);
  71. 			} else if(op == '-'){
  72. 				op1 = pop(number);
  73. 				op2 = pop(number);
  74. 				n = op2-op1;
  75. 				push(number, n);
  76. 			} else if(op == '*'){
  77. 				n = pop(number)*pop(number);
  78. 				push(number, n);
  79. 			}
  80. 		}
  81. 	}
  82. 	printf("Evaluation: %d\n", pop(number));
  83. 	free(number);
  84. 	free(operator);
  85.  
  86. 	return 0;
  87. }
  88.  
Success #stdin #stdout 0s 2188KB
comments (?)
stdin
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(5*(((9+8)*(4*6))+7))
stdout
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Evaluation: 2075
https://ideone.com/rOPyQD
language:
C (gcc 8.3)
created:
10 years ago
visibility:
public

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