如何检查数组中的重复项，然后对它们的值进行处理？

Question

I have an array for example( "1:2","5:90","7:12",1:70,"29:60" ) Wherein ID and Qty are separated by a ':' (colon), what I want to do is when there's a duplicate of IDs the program will add the qty and return the new set of arrays so in the example it will become ("1:72","5:90","7:12","29:60").

Ex.2 ( "1:2","5:90","7:12","1:70","29:60","1:5" ) becomes ( "1:77","5:90","7:12","29:60" ).

I want to solve it without using linq.

Answer 1

var foo = array.Select(s => s.Split(':'))
               .GroupBy(x => x[0])
               .Select(g => 
                    String.Format(
                        "{0}:{1}",
                        g.Key,
                        g.Sum(x => Int32.Parse(x[1]))
                    )
               )
               .ToArray();

Note, it's not necessary to parse the "keys," only the values.

Without LINQ:

var dictionary = new Dictionary<string, int>();
foreach (var group in array) {
    var fields = group.Split(':');
    if (!dictionary.ContainsKey(fields[0])) {
        dictionary.Add(fields[0], 0);
    }
    dictionary[fields[0]] += Int32.Parse(fields[1]);
}
string[] foo = new string[dictionary.Count];
int index = 0;
foreach (var kvp in dictionary) {
    foo[index++] = String.Format("{0}:{1}", kvp.Key, kvp.Value);
}

Answer 2

You have to do this manually. Loop through each list, check the ID for each element. Put it in a Dictionary<int, int> , Dictionary<id, qt> . If the dictionary contains the id, add it to the value.

1. Loop, add, check using Dictionary class.

Answer 3

(
    from raw in arr
        let splitted = raw.Split(':')
        let id = int.Parse(splitted[0])
        let qty = int.Parse(splitted[1])
        let data = new { id, qty }
        group data by data.id into grp
            let totalQty = grp.Sum(val => val.qty)
            let newStr = string.Format("{0}:{1}", grp.Key, totalQty
            select newStr
)
.ToArray()

Note that the code may contain accidental errors, as it was written in notepad.

Answer 4

var input=new string[]{"1:2","5:90","7:12","1:70","29:60","1:5"};
var result=input
             .Select(s=>s.Split(':'))
             .Select(x=>x.Select(s=>int.Parse(s)).ToArray())
             .GroupBy(x=>x[0])
             .Select(g=>g.Key+":"+g.Sum(x=>x[1]));

I was too lazy to specify the culture everywhere. You probably want to do that before putting it into production, or it will fail for cultures with unusual integer representations.

var totals=new Dictionary<int,int>
foreach(string s in input)
{
  string[] parts=s.Split(':');
  int id=int.Parse(parts[0]);
  int quantity=int.Parse(parts[0]);
  int totalQuantity;
  if(!totals.TryGetValue(id,out totalQuantity))
      totalQuantity=0;//Yes I know this is redundant
  totalQuanity+=quantity;
  totals[id]=totalQuantity;
}
var result=new List<string>();
foreach(var pair in totals)
{
  result.Add(pair.Key+":"+pair.Value);
}

Answer 5

If you want it without LINQ...

var totalQuantities = new Dictionary<int, int>();
foreach(var raw in sourceArr) {
    var splitted = raw.Split(':');
    int id = int.Parse(splitted[0]);
    int qty = int.Parse(splitted[1]);
    if(!totalQuantities.ContainsKey(id)) {
        totalQuantities[id] = 0;
    }
    totalQuantities[id] += qty;
}

var result = new string[totalQuantities.Count];
int i=0;
foreach(var kvp in totalQuantities) {
    result[i] = string.Format("{0}:{1}", kvp.Key, kvp.Value);
    i++;
}

Answer 6

try this:

List<string> items = new List<string>(new string[] { "1:2", "5:90", "7:12", "1:70", "29:60" });
Dictionary<string, int> dictionary = new Dictionary<string, int>();

foreach (string item in items)
{
    string[] data = item.Split(':');
    string key = data[0];

    if (!dictionary.ContainsKey(data[0]))
    {
        int value = dictionary[data[0]];
        dictionary[key] += int.Parse(data[1]);
    }
}

//Used dictionary values here