Sum of large numbers in C - Revision history

Arjun Suresh at 15:54, 17 June 2014

2014-06-17T15:54:42Z

2014-06-17T15:54:29Z

2014-05-09T16:57:18Z

2014-05-09T16:56:41Z

2014-05-09T16:51:03Z

2014-05-09T16:41:51Z

2014-05-09T15:36:53Z

2014-05-09T15:35:32Z

2014-05-09T14:30:28Z

2014-05-06T13:25:23Z

← Older revision		Revision as of 15:54, 17 June 2014
Line 1:		Line 1:
−	Write a program which can do sum of large numbers having ~~upto~~ 1000 digits	+	Write a program which can do sum of large numbers having up to 1000 digits

	==={{Template:Author\|Arjun Suresh\|{{arjunweb}} }}===		==={{Template:Author\|Arjun Suresh\|{{arjunweb}} }}===

← Older revision		Revision as of 15:54, 17 June 2014
Line 1:		Line 1:
		+	Write a program which can do sum of large numbers having upto 1000 digits

		+	==={{Template:Author\|Arjun Suresh\|{{arjunweb}} }}===

	<syntaxhighlight lang="c" name="largesum">		<syntaxhighlight lang="c" name="largesum">

@@ Line 47: / Line 47: @@
          c[0] = carry;//Assigning the final carry
 	return l+1;//Return the no. of digits of output
 int read(char *a)
+{
@@ Line 65: / Line 65: @@
 	return i;//Return the no. of digits read
+}
 void print(char *a, int l)
+{

@@ Line 24: / Line 24: @@
 int sum(char *a, char* b, char * c, int al, int bl)
+{
-	 int l = al > bl? al:bl;//l stores the no.of digit of output which may become l+1 due to carry from MSB
+	int l = al > bl? al:bl;//l stores the no.of digit of output which may become l+1 due to carry from MSB
          int i = l;
          char carry = 0;

@@ Line 8: / Line 8: @@
 void print(char *a, int l);
 int read(char *a);
+int sum(char *a, char* b, char * c, int al, int bl);
 int main(void) {
-	char a[1000], b[1000], c[1000], carry; //a and b hold the input numbers and c hold the output number. Each array entry is a digit
+	char a[1000], b[1000], c[1000]; //a and b hold the input numbers and c hold the output number. Each array entry is a digit
 	int al, bl; //for storing the number of digits of the two input numbers
 	printf("Enter the first number ");
@@ Line 16: / Line 16: @@
 	printf("Enter the second number ");
 	bl = read(b);
-	int l = al > bl? al:bl;//l stores the no.of digit of output which may become l+1 due to carry from MSB
+	int l = sum(a, b, c, al, bl);
 	printf("sum = ");
-	print(c, l+1);
+	print(c, l);
 	return 0;
+}
 int read(char *a)
+{
@@ Line 57: / Line 63: @@
 		c = getchar();
+	}
-	return i;
+	return i;//Return the no. of digits read
+}
 void print(char *a, int l)
@@ Line 63: / Line 69: @@
 	int i;
 	if(a[0] != 0)
-		printf("%d", a[0]);
+		printf("%d", a[0]);//If final carry is 0, ignore it
 	for(i = 1; i < l; i++)
+	{

@@ Line 51: / Line 51: @@
 		c = getchar();
+	}
-	while(isspace(c));
+	while(isspace(c)); //Reading and discarding any whitespace char typed
 	while(isdigit(c))
+	{

@@ Line 5: / Line 5: @@
 #include <string.h>
 #include <ctype.h>
-−
 void print(char *a, int l);
 int read(char *a);
-−
 int main(void) {
 	char a[1000], b[1000], c[1000], carry; //a and b hold the input numbers and c hold the output number. Each array entry is a digit
@@ Line 14: / Line 14: @@
 	printf("Enter the first number ");
 	al = read(a);
 	printf("Enter the second number ");
 	bl = read(b);
@@ Line 43: / Line 42: @@
 	return 0;
+}
-−
 int read(char *a)
+{
 	char c;
 	int i = 0;
-	while(1)
+	do
+	{
 		c = getchar();
-		if(!isdigit(c))
-			break;
+	while(isspace(c));
 		a[i++] = c - 48; //getchar returns the ASCII. So, for 1 it returns 49. Subtracting 48, we get the actual int value entered via keyboard
+	}
 	return i;
@@ Line 68: / Line 70: @@
 	printf("\n");
+}
 </syntaxhighlight>

@@ Line 3: / Line 3: @@
 <syntaxhighlight lang="c" name="largesum">
 #include <stdio.h>
-#include<string.h>
+#include <string.h>
-#include<ctype.h>
+#include <ctype.h>
 void print(char *a, int l);

@@ Line 29: / Line 29: @@
+	{
 		char val = a[--al]  + carry;
-                 c[i--] = val %10;
+                 c[i--] = val % 10;
-                 carry =   val/10;
+                 carry =   val / 10;
+	}
 	while(bl > 0)//If b has more digits than a