Prof Sedwick: https://www.coursera.org/course/algs4partI
As @carise said, the content may be gone after June 30th and if you want to download, you can do so using coursera-dl tool
 Prof Roughgarden: https://www.coursera.org/learn/algorithm-design-analysis
 Prof Erik Demaine (MIT OpenCourseware): https://www.youtube.com/playlist?list=PLUl4u3cNGP61Oq3tWYp6V...
There are videos of MIT's Prof Erik Demaine's Intro to Algo's from various semesters. I think any one should do.