LeetCode -- Substring with Concatenation of All Words

public class Solution {
    public IList<int> FindSubstring(string s, string[] words) {
        
   	if(string.IsNullOrWhiteSpace(s) || words == null || s.Length < words.Length * words[0].Length){
		return new List<int>();
	}
	
	
	var wLen = words[0].Length;
	var result = new List<int>();
	var len = words.Length * wLen;
		
	var hash = new Dictionary<string, int>();
	for(var i = 0;i < words.Length; i++){
		if(!hash.ContainsKey(words[i])){
			hash.Add(words[i], 1);
		}
		else{
			hash[words[i]] ++;
		}
	}
	
	var h = new Dictionary<string, int>();
	for(var i = 0; i < s.Length - len + 1; i++){
		for(var j = 0;j < words.Length; j++){
			var str = s.Substring(i + j * wLen, wLen);
			if(hash.ContainsKey(str)){
				if(!h.ContainsKey(str)){
					h.Add(str,1);
				}
				else{
					h[str] ++;
				}
			}
		}
		
		if(hash.All(x=>h.ContainsKey(x.Key) && h[x.Key] == x.Value)){
			result.Add(i);
		}
		
		var k2 = new List<string>(h.Keys);
		foreach(var k in k2){
			h[k] = 0;
		}
	}
	
	
	return result;
    }
}

LeetCode -- Substring with Concatenation of All Words

原文：http://blog.csdn.net/lan_liang/article/details/47660233