DSA · Theory

Detect Cycle in Graph using DSU

Theory

521/810

Detect Cycle in Graph using DSU

Detect Cycle in Graph using DSU is a DSA topic. In plain words you use it for bus routes in a city map. Don’t start with a slogan — start with that picture.

Smallest example: BFS queue / DFS stack. Type it, run it, and say what you see. If you can do that from memory, you know Detect Cycle in Graph using DSU.

From the example next to this theory: Detect Cycle in Graph using DSU — graphs are often stored as adjacency lists: vertex → list of (neighbor, weight).

Trap — no visited set → infinite loop. Fix that before you talk about advanced DSA.

Viva — what is Detect Cycle in Graph using DSU? Then show BFS queue / DFS stack. Then name the trap.

Exam tip

What is Detect Cycle in Graph using DSU? Show this: BFS queue / DFS stack. Trap: no visited set → infinite loop.

Example

# adjacency list
graph = {
    "A": [("B", 2), ("C", 5)],
    "B": [("A", 2), ("C", 1)],
    "C": [("A", 5), ("B", 1)],
}
for u, edges in graph.items():
    print(u, "->", edges)

Detect Cycle in Graph using DSU — graphs are often stored as adjacency lists: vertex → list of (neighbor, weight).

Short notes

DefDetect Cycle in Graph using DSU — bus routes in a city map.
RuleBFS queue / DFS stack
Trapno visited set → infinite loop
Usea city map

DSA · Theory

Detect Cycle in Graph using DSU

← All stacks

Theory

521/810

Detect Cycle in Graph using DSU

Detect Cycle in Graph using DSU is a DSA topic. In plain words you use it for bus routes in a city map. Don’t start with a slogan — start with that picture.

Smallest example: BFS queue / DFS stack. Type it, run it, and say what you see. If you can do that from memory, you know Detect Cycle in Graph using DSU.

From the example next to this theory: Detect Cycle in Graph using DSU — graphs are often stored as adjacency lists: vertex → list of (neighbor, weight).

Trap — no visited set → infinite loop. Fix that before you talk about advanced DSA.

Viva — what is Detect Cycle in Graph using DSU? Then show BFS queue / DFS stack. Then name the trap.

Exam tip

What is Detect Cycle in Graph using DSU? Show this: BFS queue / DFS stack. Trap: no visited set → infinite loop.

Example

# adjacency list
graph = {
    "A": [("B", 2), ("C", 5)],
    "B": [("A", 2), ("C", 1)],
    "C": [("A", 5), ("B", 1)],
}
for u, edges in graph.items():
    print(u, "->", edges)

Detect Cycle in Graph using DSU — graphs are often stored as adjacency lists: vertex → list of (neighbor, weight).

Short notes

DefDetect Cycle in Graph using DSU — bus routes in a city map.
RuleBFS queue / DFS stack
Trapno visited set → infinite loop
Usea city map

Detect Cycle in Graph using DSU

Example

Short notes

Questions

Detect Cycle in Graph using DSU

Example

Short notes

Questions