using System;
class Program
{
static int smaller_index(int []arr, int pos) {
int index = -1;
for (int i = pos - 1; i >= 0 && index == -1; i--) {
if (arr[i] < arr[pos]) {
index = i;
}
}
return index;
}
static void nearest_smaller(int []arr) {
int index = 0, size = arr.Length;
for (int i = 0; i < size; i++) {
index = smaller_index(arr, i);
if (index == -1) {
Console.WriteLine(arr[i] + " : No Smaller");
}
else {
Console.WriteLine(arr[i] + " : " + arr[index]);
}
}
}
static void Main() {
int []arr = {4, 6, 2, 8, 6, 1, 9, 12, 3, 20, 18, 30};
nearest_smaller(arr);
}
}
/*
run:
4 : No Smaller
6 : 4
2 : No Smaller
8 : 2
6 : 2
1 : No Smaller
9 : 1
12 : 9
3 : 1
20 : 3
18 : 3
30 : 18
*/
