Data commit

Task/Commatizing-numbers/Go/commatizing-numbers.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+    "fmt"
+    "regexp"
+    "strings"
+)
+
+var reg = regexp.MustCompile(`(\.[0-9]+|[1-9]([0-9]+)?(\.[0-9]+)?)`)
+
+func reverse(s string) string {
+    r := []rune(s)
+    for i, j := 0, len(r)-1; i < len(r)/2; i, j = i+1, j-1 {
+        r[i], r[j] = r[j], r[i]
+    }
+    return string(r)
+}
+
+func commatize(s string, startIndex, period int, sep string) string {
+    if startIndex < 0 || startIndex >= len(s) || period < 1 || sep == "" {
+        return s
+    }
+    m := reg.FindString(s[startIndex:]) // this can only contain ASCII characters
+    if m == "" {
+        return s
+    }
+    splits := strings.Split(m, ".")
+    ip := splits[0]
+    if len(ip) > period {
+        pi := reverse(ip)
+        for i := (len(ip) - 1) / period * period; i >= period; i -= period {
+            pi = pi[:i] + sep + pi[i:]
+        }
+        ip = reverse(pi)
+    }
+    if strings.Contains(m, ".") {
+        dp := splits[1]
+        if len(dp) > period {
+            for i := (len(dp) - 1) / period * period; i >= period; i -= period {
+                dp = dp[:i] + sep + dp[i:]
+            }
+        }
+        ip += "." + dp
+    }
+    return s[:startIndex] + strings.Replace(s[startIndex:], m, ip, 1)
+}
+
+func main() {
+    tests := [...]string{
+        "123456789.123456789",
+        ".123456789",
+        "57256.1D-4",
+        "pi=3.14159265358979323846264338327950288419716939937510582097494459231",
+        "The author has two Z$100000000000000 Zimbabwe notes (100 trillion).",
+        "-in Aus$+1411.8millions",
+        "===US$0017440 millions=== (in 2000 dollars)",
+        "123.e8000 is pretty big.",
+        "The land area of the earth is 57268900(29% of the surface) square miles.",
+        "Ain't no numbers in this here words, nohow, no way, Jose.",
+        "James was never known as 0000000007",
+        "Arthur Eddington wrote: I believe there are " +
+            "15747724136275002577605653961181555468044717914527116709366231425076185631031296" +
+            " protons in the universe.",
+        "   $-140000±100 millions.",
+        "6/9/1946 was a good year for some.",
+    }
+    fmt.Println(commatize(tests[0], 0, 2, "*"))
+    fmt.Println(commatize(tests[1], 0, 3, "-"))
+    fmt.Println(commatize(tests[2], 0, 4, "__"))
+    fmt.Println(commatize(tests[3], 0, 5, " "))
+    fmt.Println(commatize(tests[4], 0, 3, "."))
+    for _, test := range tests[5:] {
+        fmt.Println(commatize(test, 0, 3, ","))
+    }
+}