package main
import (
"fmt"
"golang.org/x/text/unicode/norm"
)
// > go run /tmp/unicode.go
// single accent NFC: é
// "\u00e9"
//
// single accent NFD: é
// "e\u0301"
//
// mutli accent NFD: é́
// "e\u0301\u0301"
//
// mutli accent NFC: é́
// "\u00e9\u0301"
func main() {
fmt.Print("single accent NFC: ")
e := "\u00e9"
fmt.Printf("%s\n", e)
fmt.Printf("%+q\n", e)
fmt.Print("\nsingle accent NFD: ")
e2 := norm.NFD.String(e)
fmt.Printf("%s\n", e2)
fmt.Printf("%+q\n", e2)
fmt.Print("\nmutli accent NFD: ")
e3 := norm.NFD.String("e\u0301\u0301")
fmt.Printf("%s\n", e3)
fmt.Printf("%+q\n", e3)
fmt.Print("\nmutli accent NFC: ")
e4 := norm.NFC.String(e3)
fmt.Printf("%s\n", e4)
fmt.Printf("%+q\n", e4)
}package main
import (
"log"
"net"
)
// Client
//
// ➜ ss nc 127.0.0.1 10080
// ➜ ss nc 127.0.0.1 10080
// ➜ ss nc 127.0.0.1 10080
// ➜ ss nc 127.0.0.1 10080
// ➜ ss nc 127.0.0.1 10080
// Server
//
// ➜ ss go run /tmp/port.go
// 2018/01/16 23:15:39 127.0.0.1:10080 -> 127.0.0.1:59513
// 2018/01/16 23:15:40 127.0.0.1:10080 -> 127.0.0.1:59514
// 2018/01/16 23:15:41 127.0.0.1:10080 -> 127.0.0.1:59515
// 2018/01/16 23:15:42 127.0.0.1:10080 -> 127.0.0.1:59517
// 2018/01/16 23:15:42 127.0.0.1:10080 -> 127.0.0.1:59518
func main() {
ln, err := net.Listen("tcp", ":10080")
if err != nil {
log.Fatal(err)
}
for {
conn, err := ln.Accept()
if err != nil {
log.Fatal(err)
}
go func(conn net.Conn) {
log.Println(conn.LocalAddr(), "->", conn.RemoteAddr())
conn.Close()
}(conn)
}
}sudo tcpdump -A -s0 -ilo0 src port 9000
sudo tcpdump -A -s0 -ilo0 dst port 9000nc -vz IP_Address Portclass BSearch {
public static void main(String[] args) {
BSearch s = new BSearch();
int l0 = s.lsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 5);
int l1 = s.lsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 6);
int l2 = s.lsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 12);
int l3 = s.lsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 13);
int l4 = s.lsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 0);
int l5 = s.lsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 1);
int r0 = s.rsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 5);
int r1 = s.rsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 6);
int r2 = s.rsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 12);
int r3 = s.rsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 13);
int r4 = s.rsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 0);
int r5 = s.rsearch(new int[]{1,2,3,4,5,5,5,5,9,12}, 1);
System.out.println("" + l0 + "," + r0);
System.out.println("" + l1 + "," + r1);
System.out.println("" + l2 + "," + r2);
System.out.println("" + l3 + "," + r3);
System.out.println("" + l4 + "," + r4);
System.out.println("" + l5 + "," + r5);
// ➜ tmp java BSearch
// 4,7
// 7,8
// 9,9
// 9,10
// -1,0
// 0,0
}
// Return the index of the first target in nums if there is one
// or the index of the last element < target
//
// suppose that nums[-1] = MIN_VALUE and nums[length] == MAX_VALUE;
// The function guarantees that nums[ret] <= target && nums[ret+1] > target
public int lsearch(int[] nums, int target) {
if (nums[0] > target) return -1;
if (nums[nums.length-1] < target) return nums.length - 1;
int l = 0;
int r = nums.length-1;
// invariant: nums[r] >= target && nums[0..l-1] < target
while (l < r) {
int m = (l+r)/2;
if (nums[m] < target) l = m+1;
else r = m;
}
// now we have:
// (1) l == r
// (2) nums[r] >= target && nums[0..l-1] < target;
//
// => nums[r] >= target && nums[0, r-1] < target
if (nums[r] == target) return r;
return r-1;
}
// the counterpart of lsearch
public int rsearch(int[] nums, int target) {
if (nums[0] > target) return 0;
if (nums[nums.length-1] < target) return nums.length;
if (nums[nums.length-1] == target) return nums.length - 1;
int l = 0;
int r = nums.length-1;
// invariant: nums[r] > target && nums[0..l-1] <= target
while (l < r) {
int m = (l+r)/2;
if (nums[m] <= target) l = m+1;
else r = m;
}
if (l > 0 && nums[l-1] == target) return l-1;
return l;
}
}