Algorithms and Data Structures : Springer : 9783540424239 : 3540424237 : 25 Jul 2001 : The papers in this volume were presented at the Seventh Workshop on Al- rithms and Data Structures (WADS 2001). The workshop took place August 8?10, 2001 in Providence, Rhode Island, USA. The workshop alternates with the Scandinavian Workshop on Algorithms Theory (SWAT), continuing the t- dition of SWAT and WADS starting with SWAT '88 and WADS '89. In response to the call for papers, 89 papers were submitted. From these submissions, the program committee selected 40 papers for presentation at the workshop. In addition invited plenary lectures were given by the following - stinguished researchers: Mikhail J. Atallah, F. Thomson Leighton, and Mihalis Yannakakis. On behalf of the program committee, we would like to express our apprec- tion to the invited speakers and to all the authors who submitted papers. August 2001 Frank Dehne J¨ org-Rudiger ¨ Sack Roberto Tamassia Organization Conference Chair Robe