LC: 3542: Minimum Operations to Convert All Elements to Zero

18 May 2025

Solution 1 – Timeout O(n²)

func minOperations(nums []int) int {
    var ops int
 
    for idx,curDigit := range nums {
        if curDigit==0{
            continue
        }
 
         
        nums[idx]=0
        ops++
        for i:=idx+1;i<len(nums);i++{
             
            if nums[i]==curDigit{
                nums[i]=0
                continue
            }
 
            if nums[i]==0 {                
                break
            }
 
            if nums[i] < curDigit{
                break
            }
        }        
         
    }
 
    return ops
}

Solution 2 – Using stack

type Stack struct {
    data []int
}
 
func (stk *Stack) push(data int) {
    stk.data = append(stk.data, data)
}
 
func (stk *Stack) pop() int {
    if len(stk.data) == 0 {
        return -1
    }
    top := stk.data[len(stk.data)-1]
    stk.data = stk.data[:len(stk.data)-1]
    return top
}
 
func (stk *Stack) peek() int {
    if len(stk.data) == 0 {
        return -1
    }
    return stk.data[len(stk.data)-1]
}
 
func (stk *Stack) len() int {
    return len(stk.data)
}
 
func minOperations(nums []int) int {
    var ops int   
    var stack Stack
    for _,curDigit := range nums {
        for curDigit<stack.peek(){
            ops++
            stack.pop()
        }
        if  curDigit>0 && stack.peek()!=curDigit {
            stack.push(curDigit)
        }        
    }    
 
    return ops+stack.len()
}