Data commit

Task/Range-extraction/C/range-extraction.c

@@ -0,0 +1,36 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+size_t rprint(char *s, int *x, int len)
+{
+#define sep (a > s ? "," : "") /* use comma except before first output */
+#define ol (s ? 100 : 0)       /* print only if not testing for length */
+	int i, j;
+	char *a = s;
+	for (i = j = 0; i < len; i = ++j) {
+		for (; j < len - 1 && x[j + 1] == x[j] + 1; j++);
+
+		if (i + 1 < j)
+			a += snprintf(s?a:s, ol, "%s%d-%d", sep, x[i], x[j]);
+		else
+			while (i <= j)
+				a += snprintf(s?a:s, ol, "%s%d", sep, x[i++]);
+	}
+	return a - s;
+#undef sep
+#undef ol
+}
+
+int main()
+{
+	int x[] = {	0,  1,  2,  4,  6,  7,  8, 11, 12, 14,
+			15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
+			25, 27, 28, 29, 30, 31, 32, 33, 35, 36,
+			37, 38, 39 };
+
+	char *s = malloc(rprint(0, x, sizeof(x) / sizeof(int)) + 1);
+	rprint(s, x, sizeof(x) / sizeof(int));
+	printf("%s\n", s);
+
+	return 0;
+}