add trick example of greatest-common-divisor, knuth-morris-pratt, primality-test, quick-pow, split-text

trick/split-text.cpp

@@ -0,0 +1,13 @@
+#include <vector>
+#include <string>
+
+std::vector<std::string> split(std::string target, std::string pattern) {
+    std::vector<std::string> res;
+    size_t start = 0, next = 0;
+    while ((next = target.find(pattern, start)) != std::string::npos) {
+        res.push_back(target.substr(start, next - start));
+        start = next + pattern.length();
+    }
+    res.push_back(target.substr(start));
+    return res;
+}