show how many nos. are smaller than current no.

no-smaller-than-current.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+   "fmt"
+)
+
+func main() {
+
+    nums := []int{8,1,2,3,2,4}
+    //sort the list with O(nlog(n))
+    nums_sorted := MergeSort(nums)
+
+    fmt.Printf("Sorted list:%d\n", nums_sorted)
+    fmt.Println()
+
+    m := make(map[int]int)
+    for i:=0; i<len(nums_sorted); i++ {
+        _, ok := m[nums_sorted[i]]
+        if ok == false {
+            m[nums_sorted[i]] = i
+        } else {
+            m[nums_sorted[i]] = m[nums_sorted[i]]
+        }
+    }
+
+    nums_out := []int{}
+    for i:=0; i<len(nums); i++ {
+        nums_out = append(nums_out, m[nums[i]])
+    }
+
+    fmt.Printf("Numbers in the current array: %d \n", nums)
+    fmt.Println()
+    fmt.Printf("Numbers smaller than current no: %d \n", nums_out)
+
+}
+
+func MergeSort(s []int) []int {
+    if len(s) <= 1 {
+        return s
+    }
+    n := len(s)/2
+    l := MergeSort(s[:n])
+    r := MergeSort(s[n:])
+
+    return Merge(l, r)
+}
+
+func Merge(l, r []int) []int {
+    ret := []int {}
+    for len(l) > 0 || len(r) > 0 {
+        if len(l) == 0 {
+            return append(ret, r...)
+        }
+        if len(r) == 0 {
+            return append(ret, l...)
+        }
+        if l[0] < r[0] {
+            ret = append(ret, l[0])
+            l = l[1:]
+        } else {
+            ret = append(ret, r[0])
+            r = r[1:]
+        }
+    }
+    return ret
+}