Difference between this C and C++ code

[Gulshan Singh]

I was looking at this very easy problem (http://www.codechef.com/AUG13/problems/SPCANDY/ ) and decided that I should do it in C just so I could brush up my C. After numerous attempts, I wasn't able to solve the problem. I was able to solve it on my first attempt using C++. Could someone tell me what the difference between both of my solutions is? Could someone try submitting a C solution and show me what I'm doing wrong?

C:

  #include <stdio.h>
#include <stdint.h>

int main() {
	uint8_t t, i;
	uint64_t n, k;

	scanf("%hhu", &t);
	for (i = 0; i < t; i++) { 
		scanf("%lu %lu", &n, &k);
		if (k == 0) {
			printf("%u %lu\n", 0, n);
		} else {
			printf("%lu %lu\n", n / k, n % k);
		}
	}
}

C++:

#include <stdint.h>
#include <iostream>

using namespace std;

int main() {
	int t, i;
	long long int n, k;

	cin >> t;
	for (i = 0; i < t; i++) { 
		cin >> n >> k;
		if (k == 0) {
			cout << 0 << " " << n << endl;
		} else {
			cout << n / k << " " << n % k << endl;
		}
	}
}

I generally prefer to use specific uintX_t types, but I was having an issue with that with cin/cout. I tried the C code using int/long int and it still failed.

[Dy7SLyTq]

a) your link is broken.
b) in c you were probably scanning wrong (i would personally just use longs)

[Gulshan Singh]

Link is fixed, the parenthesis became part of the link.

I did try one submission where I used int instead of uint8_t and long int instead of uint64_t, but I still got a wrong answer. The only other thing I changed in that submission was that the "hhu" format string became a "d".

[cire]

The following worked fine. Note that %lu isn't necessarily the correct format specifier for a uint64_t. I don't see much point in using the uintXX_t types when there is no way to specify a corresponding type in scanf/printf. Using the %j format specifier and uintmax_t would make sense, but Code Chef's C compiler doesn't have C99 enabled. (I'm glad to see they finally put up a C++11 option.)

#include <stdio.h>

int main()
{
    unsigned testCases;
    scanf("%u", &testCases);

    unsigned i;
    for (i = 0; i < testCases; ++i)
    {
        unsigned long long nCandies, nStudents;
        scanf("%llu %llu", &nCandies, &nStudents);

        if (nCandies == 0)
            printf("0 0\n");
        else if (nStudents == 0)
            printf("0 %llu\n", nCandies);
        else
            printf("%llu %llu\n", nCandies / nStudents, nCandies % nStudents);
    }
}

[Cubbi]

I don't see much point in using the uintXX_t types when there is no way to specify a corresponding type in scanf/printf.

Each of those types comes with corresponding defines that expand to the correct conversion specifiers for printf and scanf. PRId8, SCNiLEAST64, PRIxPTR, etc - they are in <cinttypes> / <inttypes.h>

[cire]

Aha. Thanks, Cubbi.

I see it's easy enough to find via search. I'd just never looked.