Download Add two strings representing numbers

Add two strings representing numbers
Need:
n = '8877463' % A number as a string
length(n) % The number of digits in n
n(length(n)) % The LSD – in this case 3
th
n(length(n)­i+1) % The i LSD
n1 = n(x) – '0' % Convert a char to a number
s = n1 + n2 % Now we can add
mod(s,10) % LSD of the add
floor(s/10) % Carry digit
char(s+'0') % Convert to a char
Add two strings representing numbers
S1 =
8
4
2
1
5
7
3
6
8
9
+
S2 =
carry = 0
S3 =
Add two strings representing numbers
S1 =
8
4
2
1
7
3
6
8
5
+
S2 =
9
carry = 0
S3 =
First iteration (i=1):
n1 = S1(length(S1)­i+1)­'0';
Add two strings representing numbers
S1 =
8
4
2
1
+
S2 =
9
7
3
6
8
carry = 0
S3 =
5
First iteration (i=1):
n2 = S2(length(S2)­i+1)­'0';
Add two strings representing numbers
S1 =
8
4
2
1
+
S2 =
9
7
3
6
8
1 4
carry = 0
S3 =
5
First iteration (i=1):
n = n1 + n2 + carry;
Add two strings representing numbers
S1 =
8
4
2
1
+
S2 =
9
7
3
6
8
1 4
carry = 1
S3 =
5
First iteration (i=1):
carry = floor(n/10);
Add two strings representing numbers
S1 =
8
4
2
1
+
S2 =
9
7
3
6
8
1 4
tmp
carry = 1
S3 =
5
First iteration (i=1):
tmp = char(mod(n,10)+'0');
Add two strings representing numbers
S1 =
8
4
2
5
1
+
S2 =
9
7
3
6
8
4
S3 =
1 4
First iteration (i=1):
S3 = [tmp S3];
carry = 1
Add two strings representing numbers
S1 =
8
4
2
1
5
7
3
6
8
9
+
S2 =
4
S3 =
Second iteration (i=2):
carry = 1
Add two strings representing numbers
S1 =
8
4
2
7
3
6
5
1
+
S2 =
S3 =
8
9
4
Second iteration (i=2):
n1 = S1(length(S1)­i+1)­'0';
carry = 1
Add two strings representing numbers
S1 =
8
4
2
5
8
+
S2 =
S3 =
1
7
3
6
9
4
Second iteration (i=2):
n2 = S2(length(S2)­i+1)­'0';
carry = 1
Add two strings representing numbers
S1 =
8
4
2
5
8
+
S2 =
7
3
6
S3 =
1
Second iteration (i=2):
n = n1 + n2 + carry;
9
1 0
4
carry = 1
Add two strings representing numbers
S1 =
8
4
2
5
8
+
S2 =
7
3
6
S3 =
1
Second iteration (i=2):
carry = floor(n/10);
9
1 0
4
carry = 1
Add two strings representing numbers
S1 =
8
4
2
5
8
+
S2 =
S3 =
1
7
3
6
9
4
Second iteration (i=2):
tmp = char(mod(n,10)+'0');
1 0
tmp
carry = 1
Add two strings representing numbers
S1 =
8
4
2
5
8
+
S2 =
7
3
6
0
S3 =
1
Second iteration (i=2):
S3 = [tmp S3];
9
1 0
4
carry = 1
Add two strings representing numbers
S1 =
8
4
2
1
5
7
3
6
8
9
0
4
+
S2 =
S3 =
Third iteration (i=3):
carry = 1