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  1. #include <stdio.h>
  2. #include <math.h>
  3. #include <string.h>
  4.  
  5. double nextval() {
  6. 	static double val;
  7. 	scanf("%lf", &val);
  8. 	return val;
  9. }
  10.  
  11. char nextop() {
  12. 	static char op[2] = "";
  13. 	if(scanf("%1s", op) < 1) // 입력의 끝?
  14. 		return '\0';
  15. 	return *op; // 연산자 리턴
  16. }
  17.  
  18. double do_calculate(double val1, char op, double val2) {
  19. 	switch(op) {
  20. 		case '+':
  21. 			return val1 + val2;
  22. 		case '-':
  23. 			return val1 - val2;
  24. 		case '*':
  25. 			return val1 * val2;
  26. 		case '/':
  27. 			return val1 / val2;
  28. 		case '^':
  29. 			return pow(val1, val2);
  30. 		case '<':
  31. 			return (double)((int)val1 * (1 << (int)val2));
  32. 		case '>':
  33. 			return (double)((int)val1 / (1 << (int)val2));
  34. 		case '&':
  35. 			return (double)((int)val1 & (int)val2);
  36. 		case '|':
  37. 			return (double)((int)val1 | (int)val2);
  38. 	}
  39. }
  40.  
  41. int check_later_is_prior(char op_first, char op_later) {
  42. 	const char *order = "^*+<&|";
  43.  
  44. 	if(op_first == '-') op_first = '+';
  45. 	else if(op_first == '/') op_first = '*';
  46. 	else if(op_first == '>') op_first = '<';
  47.  
  48. 	if(op_later == '-') op_later = '+';
  49. 	else if(op_later == '/') op_later = '*';
  50. 	else if(op_later == '>') op_later = '<';
  51.  
  52. 	return strchr(order, op_later) < strchr(order, op_first);
  53. }
  54.  
  55. double calculate(double val1, double op, double val2, char op2) {
  56. 	if(op2 == '\0') { // 연산이 더 없는 경우
  57. 		return do_calculate(val1, op, val2);
  58. 	} else {
  59. 		double nval = nextval();
  60. 		char nop = nextop();
  61.  
  62. 		if(check_later_is_prior(op, op2)) // 뒤의 연산을 더 먼저 해야하는 경우
  63. 			return do_calculate(val1, op, calculate(val2, op2, nval, nop));
  64. 		else
  65. 			return calculate(do_calculate(val1, op, val2), op2, nval, nop);
  66. 	}
  67. }
  68.  
  69. int main() {
  70. 	double val1 = nextval();
  71. 	char op1 = nextop();
  72. 	double val2 = nextval();
  73. 	char op2 = nextop();
  74. 	printf("Result: %g\n", calculate(val1, op1, val2, op2));
  75. 	return 0;
  76. }
Success #stdin #stdout 0s 3144KB
comments (?)
stdin 
10 * 2^10
stdout 
Result: 10240
https://ideone.com/B4EQoB
language:
C++14 (gcc 8.3)
created:
11 years ago
visibility:
public

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