fork download 
  1. #include <stdio.h>
  2. #include <string.h>
  3. #include <stdlib.h>
  4.  
  5. typedef struct Bigint{
  6.     char *strnum;
  7. 	unsigned int length;
  8. }* Bigint;
  9.  
  10. void strrev(char *str, int len)
  11. {
  12. 	char cpy[len];
  13. 	int i, j;
  14. 	for(i = 0, j = len - 1; j >= 0; i++, j--){
  15. 		cpy[i] = str[j];
  16. 	}
  17. 	cpy[i] = '\0';
  18. 	strcpy(str, cpy);
  19. }
  20.  
  21. Bigint bigint_new(const char *strnum)
  22. {
  23. 	Bigint bigint = malloc(sizeof(Bigint));
  24. 	int len = strlen(strnum);
  25.  
  26. 	bigint->length = len;
  27. 	bigint->strnum = malloc(len+1);
  28.  
  29. 	strcpy(bigint->strnum, strnum);
  30.  
  31. 	return bigint;
  32. }
  33.  
  34. void bigint_del(Bigint bigint)
  35. {
  36. 	free(bigint->strnum);
  37. 	free(bigint);
  38. }
  39.  
  40. void bigint_show(Bigint bigint)
  41. {
  42. 	puts(bigint->strnum);
  43. }
  44.  
  45. Bigint bigint_add(Bigint big1, Bigint big2)
  46. {
  47. 	int length = (big1->length > big2->length ? big1->length : big2->length); 
  48. 	char strnum[length + 1];
  49. 	memset(strnum, 0, length + 1);
  50.  
  51. 	int n, i1, i2, j = 0;
  52. 	for (i1 = big1->length, i2 = big2->length, j = 0;
  53. 		 i1 >= 0 && i2 >= 0;
  54. 		 --i1, --i2, ++j) {
  55. 		n = strnum[j] + (big1->strnum[i1] + big2->strnum[i2] - '0' * 2);
  56. 		if (n > 9) {
  57. 			strnum[j] = n % 10;
  58. 			strnum[j+1] = 1;
  59. 		}else{
  60. 			strnum[j] = n;
  61. 		}
  62. 	}
  63.  
  64. 	if(i1 > 0 && i2 <= 0){
  65. 		while(i1 >= 0){
  66. 			strnum[j++] += big1->strnum[i1--] - '0';
  67. 		}
  68. 	}else if(i1 <= 0 && i2 > 0){
  69. 		while(i2 >= 0){
  70. 			strnum[j++] += big2->strnum[i2--] - '0';
  71. 		}
  72. 	}
  73.  
  74. 	if(strnum[j+1] != 0){
  75. 		j++;
  76. 	}
  77.  
  78. 	int i;
  79. 	for(i = 0; i < j; i++){
  80. 		strnum[i] += '0';
  81. 	}
  82.  
  83. 	strnum[j] = '\0';
  84. 	strrev(strnum, j);
  85.  
  86. 	return bigint_new(strnum);
  87. }
  88.  
  89. int main(void)
  90. {
  91. 	Bigint num1 = bigint_new("990");
  92. 	Bigint num2 = bigint_new("900");
  93. 	Bigint num3 = bigint_add(num1, num2);
  94. 	bigint_show(num3);
  95.  
  96. 	return 0;
  97. }
  98.  
Success #stdin #stdout 0s 1964KB
comments (?)
stdin 
Standard input is empty
stdout 
1890�
https://ideone.com/2wL6Ut
language:
C (gcc 8.3)
created:
11 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!