adding some algorithms to stlite

stlite/algorithm.hpp

@@ -0,0 +1,40 @@
+#include <cstddef>
+#include <utility>
+namespace ZYM {
+template <typename T>
+void MergeSort(T *beg, T *end, bool (*cmp)(const T &, const T &)) {
+  if (end - beg <= 1) return;
+  size_t len = end - beg;
+  T *mid = beg + (len >> 1);
+  MergeSort(beg, mid, cmp);
+  MergeSort(mid, end, cmp);
+  T *tmp = new T[len];
+  T *cur_tmp = tmp, *cur_L = beg, *cur_R = mid;
+  while ((cur_L < mid) && (cur_R < end)) {
+    if (cmp(*cur_L, *cur_R))
+      *(cur_tmp++) = *(cur_L++);
+    else
+      *(cur_tmp++) = *(cur_R++);
+  }
+  while (cur_L < mid) *(cur_tmp++) = *(cur_L++);
+  while (cur_R < end) *(cur_tmp++) = *(cur_R++);
+  cur_tmp = tmp;
+  T *cur_dst = beg;
+  while (cur_dst < end) *(cur_dst++) = *(cur_tmp++);
+  delete[] tmp;
+}
+template <typename T>
+void swap(T &a, T &b) {
+  T c(std::move(a));
+  a = std::move(b);
+  b = std::move(c);
+}
+template <typename T>
+const T &min(const T &a, const T &b) {
+  return a < b ? a : b;
+}
+template <typename T>
+const T &max(const T &a, const T &b) {
+  return a > b ? a : b;
+}
+}  // namespace ZYM