Article directory
foreword
I was doing happy work (fishing), but my colleague said, are you bored? I'm bored, I'll find you something to do.
Me:
OK, OK!
1. Problems
Before you see deduplication, don’t you look down on people? It’s too simple.
After seeing the deduplication, do you look down on me too much? Who can do this.
Two, solve the problem
1. Before deduplication
First write out the unrepeated ones
fun generateCombinations(numbers: List<Int>): List<List<Int>> {
val combinations = mutableListOf<List<Int>>()
for (i in 0 until numbers.size) {
val combination = mutableListOf<Int>()
combination.add(numbers[i])
combinations.add(combination)
for (j in i + 1 until numbers.size) {
combination.add(numbers[j])
combinations.add(combination.toList())
}
}
return combinations
}
Double for loop traverses all possibilities, nothing to say
2. After deduplication
I can't do it (dog head), so what should I do, I'm not a bad showman! Then the problem came again, what should I do? ! chatgpt! ! !
fun generateCombinations(numbers: List<Int>): List<List<Int>> {
val combinations = mutableListOf<List<Int>>()
for (i in 0 until numbers.size) {
val combination = mutableListOf<Int>()
combination.add(numbers[i])
combinations.add(combination)
for (j in i + 1 until numbers.size) {
combination.add(numbers[j])
combinations.add(combination.toList())
}
}
return combinations.distinct()
}
That's right, you read that right, there is only one more distinct function, chatgpt is simply my god, let's take a look at the source code,
mom no longer has to worry about my study!
Summarize
Finally, come to a list of 1 to 256 to test
fun SummationAnddeDuplication() {
val long = System.currentTimeMillis()
val numbers = mutableListOf<Int>()
for (i in 1..256){
numbers.add(i)
}
val combinations = generateCombinations(numbers)
println("Combinations:")
combinations.forEach {
println(it) }
val long1 = System.currentTimeMillis()-long
println("Number of combinations: ${
combinations.size}" +" time : ${
long1/1000}s" )
}
fun generateCombinations(numbers: List<Int>): List<List<Int>> {
val combinations = mutableListOf<List<Int>>()
for (i in 0 until numbers.size) {
val combination = mutableListOf<Int>()
combination.add(numbers[i])
combinations.add(combination)
for (j in i + 1 until numbers.size) {
combination.add(numbers[j])
combinations.add(combination.toList())
}
}
return combinations.distinct()
}
The output
is really good, chatgpt is really useful for learning to write code!
