q.cpp

#include <cstdio>
#include <stdlib.h>

int
main(int argc, char const *argv[])
{
	int q, i, j, w, x, y, z;
	FILE *h = fopen("/tmp/input.txt", "r");
	char *r9 = (char*)malloc(32 * sizeof(char));

	fgets(r9, 32, h);
	q = atoi(r9);
	for (i = 0; i < q; ++i) {
		fgets(r9, 32, h);
		w = atoi(r9);
		fgets(r9, 32, h);
		y = atoi(r9);
		fgets(r9, 32, h);
		x = atoi(r9);
		for (z=0,j=w; j <= y; ++j) {
			if ((j % x) == 0) {
				z++;
			}
		}
		printf("case %d: %d\n", i, z);
	}
	free(r9); r9 = nullptr;
	fclose(h);
	return 0;
}