how to discover Bugs that consume resources?

hi,

this is the second time i encounter this type of bugs, when i run my program after a while i find it consumes all the power or my processor, i'm dying for three days now trying to discover this bug with no success, is there anyway to help in dicovering such a thing

2 months ago i encounter something like this, but it was consuming the rams, i found this one after hard times

i need a simple thing for beginners, or advice how to discover those bugs

thx in advance