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Tree of Blocked Courses

Tree viewer

The tool below shows you all the courses that become unlocked after taking the given courses. If the tree is too large to fit on screen, open the page in full screen and zoom out.

To try it out, try adding CSE 11 below.

The tree shows all other courses that require your selected course. To reverse the direction of the tree, click on "Prerequisites" on the top right to show the courses required by your selected course.

Faculty example: Suppose you are an administrator considering adding a prerequisite to CSE 11. Type in "CSE 11" and click "Add." A tree appears containing CSE 11 (outlined in black) and all the courses blocked by CSE 11. You can hover on each dot to see its course code. The dots are color coded by subject, and you can hover over a subject code in the legend in the bottom left corner to highlight courses by subject.

According to the legend, there are 134 courses total, including CSE 11. This means that CSE 11 blocks 133 courses. A blocked course is a course that has your selected course, CSE 11, somewhere in its prerequisite chain. For example, CSE 30 is in the tree because it requires CSE 12, and CSE 12 requires CSE 11, as shown by the arrows, so CSE 30 is blocked by CSE 11. If you add a prerequisite to CSE 11, your changes will also indirectly impact 133 other courses.

The tree will only draw arrows from the first course that blocks a course. For example, CSE 100 requires CSE 12 and CSE 30, but there will only be an arrow from CSE 12 to CSE 100, not CSE 30 to CSE 100. The tree is not intended to exhaustively show prerequisites of courses.

Student example: Suppose you are a student taking CSE 20 and CSE 30, and you want to know what courses you can take next quarter. Enable the "Only show fully unlocked courses" option. Add all of the courses you have credit for. A tree appears with all of the courses you can take in the following quarters. The dots with an arrow starting from a dot outlined in black (a course you added) represents a course you can immediately take next quarter. For example, CSE 140 has an arrow from CSE 20 and CSE 30, which are outlined in black, so you can take CSE 140 in your next quarter.

The tree uses course prerequisite data for fall 2022, accessed from the Registrar in summer 2022. This data may contain errors and historical courses.


The table below summarizes the total number of courses blocked by each course.