Treating numeric overflow for pascal triangle - c

Question

I am trying to create a large pascal triangle that prints up to 70 lines. My code works fine at first but it started to print out the wrong output when it reaches the 65th line. I know the problem to it and I've tried using GMP. Unfortunately the software that i use to code doesn't support GMP. Is there any other ways that i can do this without using GMP?
char str;
int value;
int pascal(int n)
{
for (int i = 1; i < n + 2; i++)
{
unsigned long number = 1;
for (int j = 1; j < i + 1; j++)
{
if(j == i)
{
printf("%lu\n", number);
}
else
{
printf("%lu ", number);
}
number = (number * (i - j) / j);
}
}
return 0;
}

Answer 1

Is there any other ways that i can do this without using GMP?
The integer math needed exceeds basic 64-bit math in forming numbers such as 109069992321755544170, a 67-bit number with more than 64 leading significant bits.
Although the widest integer uintmax_t may meet the more than 64-bit math needs, it is commonly only 64-bit.
long double often has a fair amount of precision (only 64-bit on my platform), but that is not specified to meet OP's need and invokes the usually FP issues of solving an integer problem.
Fortunately the extended math needed is only a multiply and divide. A simple, although not highly efficient, string multiply and divide meets the need.
void string_mult(char *y, unsigned x) {
size_t len = strlen(y);
unsigned acc = 0;
size_t i = len;
while (i > 0) {
i--;
acc += (y[i] - '0') * x;
y[i] = acc % 10 + '0';
acc /= 10;
}
while (acc) {
memmove(&y[1], &y[0], ++len);
y[0] = acc % 10 + '0';
acc /= 10;
}
}
unsigned string_div(char *y, unsigned x) {
size_t len = strlen(y);
unsigned acc = 0;
for (size_t i = 0; i < len; i++) {
acc *= 10;
acc += y[i] - '0';
y[i] = acc / x + '0';
acc %= x;
}
while (y[0] == '0' && len > 1) {
memmove(&y[0], &y[1], len);
len--;
}
return acc;
}
void pascal(unsigned n) {
printf("%u: ", n);
for (unsigned i = 1; i < n + 2; i++) {
char s[100] = "1";
for (unsigned j = 1; j <= i; j++) {
printf("%s ", s);
string_mult(s, i - j);
string_div(s, j);
}
printf("\n");
}
}
int main() {
for (unsigned i = 0; i <= 70; i++)
pascal(i);
}
Output
...
1 70 2415 54740 916895 12103014 131115985 1198774720 9440350920 65033528560 396704524216 2163842859360 10638894058520 47465835030320 193253756909160 721480692460864 2480089880334220 7877932561061640 23196134763125940 63484158299081520 161884603662657876 385439532530137800 858478958817125100 1791608261879217600 3508566179513467800 6455761770304780752 11173433833219812840 18208558839321176480 27963143931814663880 40498346384007444240 55347740058143507128 71416438784701299520 87038784768854708790 100226479430802391940 109069992321755544170 112186277816662845432 109069992321755544170 100226479430802391940 87038784768854708790 71416438784701299520 55347740058143507128 40498346384007444240 27963143931814663880 18208558839321176480 11173433833219812840 6455761770304780752 3508566179513467800 1791608261879217600 858478958817125100 385439532530137800 161884603662657876 63484158299081520 23196134763125940 7877932561061640 2480089880334220 721480692460864 193253756909160 47465835030320 10638894058520 2163842859360 396704524216 65033528560 9440350920 1198774720 131115985 12103014 916895 54740 2415 70 1
On further review, a long double may work, yet my efforts failed at pascal(69).