I made new HashMap, then in foreach I swapped values and keys and put them to new Map. Then I cleared Map and put there values and keys.
package com.codegym.task.task08.task0817;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/*
We don't need repeats
*/
public class Solution {
public static HashMap<String, String> createMap() {
//write your code here
HashMap <String, String> map = new HashMap<>();
map.put("Bob", "Dilan");
map.put("Den", "Brown");
map.put("Piter", "Parker");
map.put("Jack", "Swarrow");
map.put("Polina", "Gagarina");
map.put("Bill", "Geits");
map.put("Eshly", "Oulsen");
map.put("Jesica", "Oulsen");
map.put("Rebeca", "Oulsen");
map.put("Petya", "Parker");
return map;
}
public static void removeFirstNameDuplicates(Map<String, String> map) {
//write your code here
HashMap<String, String> newMap = new HashMap<>();
for (Map.Entry<String, String> e : map.entrySet())
newMap.put(e.getValue(), e.getKey());
map.clear();
for(Map.Entry<String, String> en : newMap.entrySet())
map.put(en.getValue(), en.getKey());
newMap.clear();
for (Map.Entry ent : map.entrySet()) {
String value = (String) ent.getValue();
removeItemFromMapByValue(map, value);
}
}
public static void removeItemFromMapByValue(Map<String, String> map, String value) {
HashMap<String, String> copy = new HashMap<String, String>(map);
for (Map.Entry<String, String> pair : copy.entrySet()) {
if (pair.getValue().equals(value))
map.remove(pair.getKey());
}
}
public static void main(String[] args) {
}
}