done

programs/p414/main.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+
+int main(void) {
+    int n;
+
+numInput:
+    printf("Input positive integer: ");
+    scanf("%d", &n);
+
+    if (n < 0) {
+        puts("Please input positive integer.");
+        goto numInput;
+    }
+
+    for (int i = 1; i <= n; i++) {
+        printf("%d", i % 10);
+    }
+
+    putchar('\n');
+
+    return 0;
+}