fix: add <cstdint> to data_structures/dsu_path_compression.cpp

data_structures/dsu_union_rank.cpp

@@ -20,6 +20,7 @@
  */
 
 #include <cassert>   /// for assert
+#include <cstdint>   /// for integral typedefs
 #include <iostream>  /// for IO operations
 #include <vector>    /// for std::vector