class HeapArray:

    def __init__(self):
        self._data = [] # indefinite size list; insert cannot fail
        self._size = 0

    def __str__(self):
        return ' '.join([str(i) for i in self._data])

    def is_empty(self):
        return self._size == 0

    def insert(self,e):
        #self._data.insert(self._size,e)
        self._data.append(e)
        index = self._size
        while index > 0 and self._data[index]  < self._data[(index-1)//2]:
            # Send value up the tree
            temp = self._data[index]
            self._data[index] = self._data[(index-1)//2]
            self._data[(index-1)//2] = temp
            index = (index-1)//2
        self._size = self._size + 1
        return True

    def delete_min(self):
        if self.is_empty():
            return None
        elif self._size == 1:
            return self._data.pop(0)
        else:
            smallest = self._data[0]
            self._data[0] = self._data.pop(self._size-1)
            self._size = self._size - 1
            index = 0
            while 2*index+1 < self._size:  # this condition means that there is at least one child
                # check if there is a second child
                if 2*index+2 < self._size: # 2 children
                    if self._data[2*index+1] < self._data[2*index+2]: # left child smaller than right child
                        if self._data[index] > self._data[2*index+1]:
                            temp = self._data[index]
                            self._data[index] = self._data[2*index+1]
                            self._data[2*index+1] = temp
                        index = 2*index+1
                    else: # right child is smaller than left child
                        if self._data[index] > self._data[2*index+2]:
                            temp = self._data[index]
                            self._data[index] = self._data[2*index+2]
                            self._data[2*index+2] = temp
                        index = 2*index+2
                else: #one child
                    if self._data[index] > self._data[2*index+1]:
                        temp = self._data[index]
                        self._data[index] = self._data[2*index+1]
                        self._data[2*index+1] = temp
                    index = 2*index+1
            return smallest
        # CASE ANALYSIS

pq1 = HeapArray()
pq1.insert(8)
pq1.insert(14)
pq1.insert(2)
pq1.insert(10)
pq1.insert(26)
pq1.insert(3)
pq1.insert(1)
sm = pq1.delete_min()
print(pq1)
print(sm)

2 10 3 14 26 8
1

result = ""
for x in ["1","2","3","4"]:
    result = result + x + ","
result = result[0:-1]
print(result)

1,2,3,4

print(','.join([str(i) for i in [1,2,3,4]]))

1,2,3,4

s = [2,5,7]
s.append(99)
print(s)

[2, 5, 7, 99]

## SWAPPING values of variables
x = 5
y = 7
temp = y
y = x
x = temp
print(x)
print(y)

7
5