# How to check if search problem has no solution in depth limit search?

#### terabaaphoonmein

Joined Jul 19, 2020
101
Depth-limited search can be terminated with two Conditions of failure:

Standard Failure: it indicates that the problem does not have any solutions.

Cutoff Failure Value: It defines no solution for the problem within a given depth limit.

https://www.analyticsvidhya.com/blog/2021/02/uninformed-search-algorithms-in-ai/

https://www.javatpoint.com/ai-uninformed-search-algorithms

I checked for cut off failure. But I don't know how to check for standard failure. Can you guide me a bit?

Python:
# Python dictionary to act as an adjacency list
graph = {
'7' : ['19','21', '14'],
'19': ['1', '12', '31'],
'21': [],
'14': ['23', '6'],
'1' : [],
'12': [],
'31': [],
'23': [],
'6' : []
}

goal='6'
visited = [] # List of visited nodes of graph.
def dls(visited, graph, node,depth):
if(depth>=0):

if node not in visited:
visited.append(node)

if(node==goal):
print("goal found")
print("path to goal=",visited)
exit()

for neighbor in graph[node]:
dls(visited, graph, neighbor,depth-1)

print(node)

# Driver Code
print("Following is the Depth-First Search")
res=dls(visited, graph, '7',1)
if(res):
print("Path to goal node available")
print("Path",path)
else:
print("No path available for the goal node in given depth limit ie cut off failure")

print("visited=",visited)