A system has n processes with a total of 7 resources. Each process needs 3 resources. What is the maximum number of N without deadlock? (analysis attached)

3
Analysis of the answer ：
Find the critical number of resources , Number of resources required per process -1, Then add it up to the number of critical resources m
Greater than m There will be no deadlock , Less than or equal to m It will lock up
process P1,P2,P3 The number of resources required is n1,n2,n3, Then the number of critical resources is （n1-1）+（n2-1）+（n3-1）
eg：
3 A process , Each process requires 5 A resource
Every process gets 4 A resource , That is, no extra resources can be reallocated to any one of them , Then there is a deadlock
If there is another redundant resource, it can be given to any process , Release after execution 5 A resource for others 4 Processes use , There will be no deadlock . At least （5-1）+（5-1）+（5-·1）+1=13 A resource , No deadlock

Go back to the original question ：
N*（3-1）+1=7, Solution n=3