I need a Sorted list, but after I remove an item from the list I then need to adjust the keys of the other items before adding new items to the list.
You are not allowed to change the key for the items in a "SortedList".
What tool would be best for doing this.
Example code
timedEvQue.Add(3, "First");
timedEvQue.Add(7, "Second");
timedEvQue.Add(9, "Third");
int decAmnt = (int)timedEvQue.Keys[0];
timedEvQue.RemoveAt(0);
for (int i = 0; i < timedEvQue.Count; ++i)
{
timedEvQue.Keys[i] = timedEvQue.Keys[i] - decAmnt; //runtime error here
}
timedEvQue.Add(5, "Forth");
There isn't typically a change key operation for dictionary/hash map type data structures as they would essentially just remove and add the item again. So just remove and add the item back.
timedEvQue.Add(3, "First");
timedEvQue.Add(7, "Second");
timedEvQue.Add(9, "Third");
int decAmnt = (int)timedEvQue.Keys[0];
timedEvQue.RemoveAt(0);
for (int i = 0; i < timedEvQue.Count; ++i)
{
int oldKey = timedEvQue.Keys[i];
string val = timedEvQue[oldKey];
int newKey = oldKey - decAmnt;
timedEvQue.Remove(oldKey);
timedEvQue.Add(newKey, val);
}
timedEvQue.Add(5, "Forth");
Related
I have a foreach of a List and i want to Update the list or (i don´t know wich is better) create a new one with the new values. How to do this ?
My code is bigger than this because i am decrypting, but if help me with this simple, will fix the other.
foreach (Envolvido envolvido in ListaDados.ItemsSource)
{
for (int i = 0; i < ListaDados.ItemsSource.OfType<object>().Count(); i++)
{
var suspid = Convert.FromBase64String(envolvido.SUSPID);
var ivnome = Convert.FromBase64String(envolvido.IVNOME);
}
}
So, with the help of all, i got the correct answer !
List<Envolvido> mylist = t.Result;
for (int index = 0; index < mylist.Count(); index++)
{
var items = mylist.ToList();
Envolvido envolvido = items[index];
envolvido.SUSPID= Convert.FromBase64String(envolvido.SUSPID);
envolvido.IVNOME = Convert.FromBase64String(envolvido.IVNOME);
}
THANKS!
Use for for modifing lists. NOT foreach.
As it says on MSDN:
The foreach statement is used to iterate through the collection to get the information that you want, but can not be used to add or remove items from the source collection to avoid unpredictable side effects. If you need to add or remove items from the source collection, use a for loop.
List<Envolvido> mylist = t.Result;
for (int index = 0; index < mylist.Count(); index++)
{
var items = mylist.ToList();
Envolvido envolvido = items[index];
envolvido.SUSPID= Convert.FromBase64String(envolvido.SUSPID);
envolvido.IVNOME = Convert.FromBase64String(envolvido.IVNOME);
}
I have a bindinglist of keyvaluepair filled dynamicaly.
BindingList<KeyValuePair<int, string>> Homelist = new BindingList<KeyValuePair<int, string>>();
foreach (ListItem item in listBox2.Items)
{
Homelist.Add(new KeyValuePair<int, string>(item.Id, item.Name));
}
The list has key(id) and value(text) as shown
I want to sort the first 5 items asc and then the rest items also asc.the sorting must be by value and not by key.
example: if I have the values : 4,5,8,7,6,10,9,3,2,1,22 the sorting result must be 4,5,6,7,8 ,1,2,3,9,10,22.Any idea?
solved answer:
public int Compare(KeyValuePair<int,string> a, KeyValuePair<int,string> b)
{
return a.Value.CompareTo(b.Value);
}
List<keyvaluepair><int,>> Playinglist = new List<keyvaluepair><int,>>();
for (int i = 0; i < 5; i ++)
{
Playinglist.Add(Homelist[i]);
}
Playinglist.Sort(Compare);
List<keyvaluepair><int,>> Benchlist = new List<keyvaluepair><int,>>();
for (int i = 5; i < Homelist.Count(); i++)
{
Benchlist.Add(Homelist[i]);
}
Benchlist.Sort(Compare);
//union 2 lists
var unionedList = new List<keyvaluepair><int,>>();
unionedList.AddRange(Playinglist.Union(Benchlist));
Homelist.Clear();
for (int i = 0; i < unionedList.Count(); i++)
{
Homelist.Insert(i, unionedList[i]);
}
game.GetHomelist = Homelist;
The idea that Tony Hopkinson said is to chop the list into two. Sort them separately and then join them back togther.After that clear the bindlist and filled from the join list. Sorting can be applied only in List<> and not to the BindLists<>.The answere is in edited question
For my homework, I have to use a SortedList to count words in a List with SortedList taking each entry and sorting it in alphabetical order before inserting. When it comes to display the data to the user, the data displayed should be displayed with sorting according to value instead of key.
Below is my attempt at this but I am getting 3 errors and I don't know how to resolve it. I am not allowed to use LINQ for this.
List<string> words = new List<string>(); <--- Already populated
This is my code of this implementation and I get 3 errors:
SortedList<string, int> d = new SortedList<string, int>();
bool InsideOfList = false;
foreach (string word in words)
{
InsideOfList = false;
foreach (KeyValuePair<string, int> keyvalPair in d)
{
if (keyvalPair.Key == word)
{
keyvalPair.Value += 1;
InsideOfList = true;
}
}
if (InsideOfList == false)
{
d.Add(word,1);
}
}
//Now instead of sorting by key I want to sort by value instead
SortedList<int, string> tempSortList = new SortedList<int, string>();
foreach (KeyValuePair<string, int> keyvalPair in d)
{
//trying to swap the value of previous SortedList with the Key of the new SortedList
tempSortList.Add(keyvalPair.Value, keyvalPair.Key);
}
for (int i = 0; i < 20; i++)
{
Console.WriteLine("\t{0}:\t{1}", tempSortList.GetKey(i), tempSortList.GetByIndex(i));
}
Here are my errors:
Property or indexer 'System.Collections.Generic.KeyValuePair<string,int>.Value' cannot be assigned to -- it is read only
'System.Collections.Generic.SortedList<int,string>' does not contain a definition for 'GetKey'
'System.Collections.Generic.SortedList<int,string>' does not contain a definition for 'GetByIndex'
You are confusing two things here. One is SortedList() and other is SortedList().
GetKey and GetKeyList are not present in SortedList(). You can use this instead of GetKey
tempSortList.ElementAt(index); // This will return you a KeyValuePair.
And for the first error you cannot assign value keyvalPair.Value has only getter. So you cannot set its value by doing += 1.
This is not quite good. Needs some improvement but it will work.
for (int i = 0; i < d.Count; i++)
{
if (d.ElementAt(i).Key == word)
{
d.Values[i] += 1;
}
}
or
for (int i = 0; i < d.Count; i++)
{
if (d.ElementAt(i).Key == word)
{
var val = d.ElementAt(i).Value + 1;
d.RemoveAt(i);
d.Add(word, val);
}
}
Please modify this line and check if it works. it should.
Console.WriteLine("\t{0}:\t{1}", tempSortList.GetKey(i), tempSortList.GetByIndex(i));
to
var key = tempSortedList.Keys[i];
var value = tempSortedList.Values[i];
Console.WriteLine("\t{0}:\t{1}", key, value);
I'm trying to put values into a dictionary dependent on the key... For example, if in a list of keys at the index 0 there is a letter "a". I want to add the val with index 0 to a list inside of a dictionary with the key "a" ( dictionary (key is "a" at index 0 , val at index 0) ... dictionary (key is "b" at index 2 , val at index 2))
I'm expecting an output like this:
in listview lv1: 1,2,4 in listview lv2: 3,5
what I'm getting is 3,4,5 in both listviews
List<string> key = new List<string>();
List<long> val = new List<long>();
List<long> tempList = new List<long>();
Dictionary<string, List<long>> testList = new Dictionary<string, List<long>>();
key.Add("a");
key.Add("a");
key.Add("b");
key.Add("a");
key.Add("b");
val.Add(1);
val.Add(2);
val.Add(3);
val.Add(4);
val.Add(5);
for (int index = 0; index < 5; index++)
{
if (testList.ContainsKey(key[index]))
{
testList[key[index]].Add(val[index]);
}
else
{
tempList.Clear();
tempList.Add(val[index]);
testList.Add(key[index], tempList);
}
}
lv1.ItemsSource = testList["a"];
lv2.ItemsSource = testList["b"];
Solution:
replace the else code section with :
testList.Add(key[index], new List { val[index] });
thx everybody for your help =)
You are using the same list for both keys in the Dictionary
for (int index = 0; index < 5; index++)
{
if (testList.ContainsKey(key[index]))
{
testList[k].Add(val[index]);
}
else
{
testList.Add(key[index], new List<long>{val[index]});
}
}
Just create one new List(Of Long) when the key doesn't exists then add the long value to it
Get rid of the tempList and replace your else clause with:
testList.Add(key[index], new List<long> { val[index] });
And don't use Contains. TryGetValue is much better:
for (int index = 0; index < 5; index++)
{
int k = key[index];
int v = val[index];
List<long> items;
if (testList.TryGetValue(k, out items))
{
items.Add(v);
}
else
{
testList.Add(k, new List<long> { v });
}
}
Replace else with:
else
{
tempList.Clear();
tempList.Add(val[index]);
testList.Add(key[index], new List<long>(tempList));
}
The problem is, you are adding a reference to TempList to both keys, it is the same reference so it gets replaced in the first one.
I am creating a new list so it doesn't get replaced: new List<long>(tempList)
Sounds like a homework problem, but
for (int index = 0; index < 5; index++)
{
if (!testList.ContainsKey(key[index]))
testList.Add(key[index], new List<string> {value[index]});
else
testList[key[index]].Add(value[index]);
}
Read this (and the other relevant tutorials)
I'm not completely sure what you are trying to do here, but I guarantee you didn't want the same list in every dictionary entry.
templist is your problem swap templist.Clear() for templist = new List<Long>()
Or go for
for (int index = 0; index < 5; index++)
{
if (!testList.ContainsKey(key[Index]))
{
testList.Add(key[Index], new List<Long>());
}
testList[key[index]].Add(val[index]);
}
Hi I have a quick question, which is the easiest way to loop inside an array that is within an object in a dictionary using C#?
The dictionary contain groups and groups have an array called tags, I have search for a tag and return a list of groups that contain that tag
I created a solution but it returns too many doubles when I apply it.
List<Programme> toReturn = new List<Programme>();
// might need to ask getprogramme service to do the iteriation and retun a value
foreach (Programme programme in programmes.Values)
{
if (message.Programme.Tags[0] != null)
{
int i;
int u;
foreach (KeyValuePair<string, Programme> entry in programmes)
{
// for (i = 0; i < message.Group.Tags.Length; i++)
for (i = 0; i < entry.Value.Tags.Length; i++)
//foreach (string i in message.Group.Tags)
{
for (u = 0; u < message.Programme.Tags.Length; u++)
{
// Compare the Name of the entry to the Name in the message (string comparison)
if (entry.Value.Tags[i].Equals(message.Programme.Tags[u]))
{
// If we found the group, set the return value and then break from the loop
toReturn.Add(programme);
break;
}
}
}
}
}
The easiest way is to use LINQ:
var res = groups.Where(g => g.Value.Any(t => t.Equals("search_tag")));