Snippets for Algorithms used in string problems

Author: MeghaSharma21

string/splitString.sublime-snippet

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+<snippet>
+	<content><![CDATA[
+	template<typename Out>
+	void split(const std::string &s, char delim, Out result) {
+	    std::stringstream ss;
+	    ss.str(s);
+	    std::string item;
+	    while (std::getline(ss, item, delim)) {
+	        *(result++) = item;
+	    }
+	}
+
+	std::vector<std::string> split(const std::string &s, char delim) {
+	    std::vector<std::string> elems;
+	    split(s, delim, std::back_inserter(elems));
+	    return elems;
+	}
+
+	// Call it as vector<string> arr = split(s, ' ');
+
+]]></content>
+	<!-- Optional: Set a tabTrigger to define how to trigger the snippet -->
+	<tabTrigger>split-string</tabTrigger>
+	<!-- Optional: Set a scope to limit where the snippet will trigger -->
+	<!-- <scope>source.python</scope> -->
+</snippet>

string/suffixArray.sublime-snippet

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+<snippet>
+	<content><![CDATA[
+	// Suffix Array and LCP Array
+	// suffix-array starts
+	struct node{
+		int sortindex[2];
+		int index;
+	};
+	int n,step;
+	map<int,int> smap;
+	vector<int> sarr;	//suffix-array
+	vector< vector<int> > rem(20);
+	bool cmp( node& a, node& b)
+	{
+		return a.sortindex[0] == b.sortindex[0] ? ( a.sortindex[1] < b.sortindex[1] ? 1 : 0 ) : ( a.sortindex[0] < b.sortindex[0] ? 1 : 0 ) ;
+	}
+
+	void suffix(string s)	//call suffix(string)
+	{
+		n = s.length();
+		sarr.reserve(n);
+		for (int i = 0; i < 20; i++)
+		{
+			rem[i].reserve(n);
+		}
+
+		node sa[n];
+		step=1;
+		int count=1;
+		for( int i = 0; i < n; i++)
+		{
+			rem[0][i] = s[i] - 'a';
+		}
+
+		for( ; count>>1 < n ; step++,count<<=1 )
+		{
+			for(int i=0 ; i<n ; i++)
+			{
+				sa[i].sortindex[0] = rem[step-1][i];
+				sa[i].sortindex[1] = i+count < n ? rem[step-1][i+count] : -1;
+				sa[i].index = i;
+			}
+			sort(sa, sa+n, cmp);
+			for(int i=0; i<n; i++)
+			{
+				rem[step][sa[i].index] = (i>0 && sa[i-1].sortindex[0]==sa[i].sortindex[0] && sa[i-1].sortindex[1]==sa[i].sortindex[1]) ? rem[step][sa[i-1].index] : i;
+			}
+		}
+
+		for (int  i = 0;  i < n;  i++) {
+			smap[rem[step-1][i]]=i;
+		}
+
+		int j=0;
+		for(auto& i : smap){
+		  sarr[j++] = i.second;
+		}
+
+	}
+
+
+	int lcp(int x, int y)		//length of lcp of suffixes starting at x and y
+	{
+		int k, ans=0;		// lcp(x,y) = min[lcp(x,x+1),lcp(x+1,x+2),lcp(x+2,x+3),....,lcp(y-1,y)]
+
+		if (x==y) {				// so, use rmq if there are too many queries
+			return n-x;
+		}
+
+		for(k=step-1; k>=0 && x<n && y<n; k--)
+		{
+			if (rem[k][x] == rem[k][y]) {
+				x += 1<<k;
+				y += 1<<k;
+				ans+= 1<<k;
+			}
+		}
+
+		return ans;
+	}
+	//suffix array ends
+]]></content>
+	<!-- Optional: Set a tabTrigger to define how to trigger the snippet -->
+	<tabTrigger>suffix-array</tabTrigger>
+	<!-- Optional: Set a scope to limit where the snippet will trigger -->
+	<!-- <scope>source.python</scope> -->
+</snippet>