[백준] 2042. 구간 합 구하기

세그먼트 트리 활용

def seg_tree(nums, oper, b, c, tree):
    def init(start, end, node, a, tree):
        if start == end: 
            tree[node] = a[start]
            return tree[node]
        mid = (start+end)//2
        tree[node] = init(start, mid, node*2, a, tree) + init(mid + 1, end, node * 2 + 1, a, tree)
        return tree[node]
 
    def sum(start,end,node,left,right, tree):
        if left > end or right < start: return 0
 
        if left <= start and end <= right: return tree[node]
 
        mid = (start+end)//2
        return sum(start, mid, node*2, left, right, tree) + sum(mid + 1, end, node*2+1, left, right, tree)
 
    def update(start, end, node, index, dif, tree, a):
        if index < start or index > end: return
        if start == end:
            tree[node] = dif
            a[index] = dif
            return
        tree[node] += dif - a[index]
        mid = (start+end) // 2
        update(start,mid, node*2,index, dif, tree, a)
        update(mid + 1, end, node*2 + 1,index, dif, tree, a)
    
    S = 0
    if oper == 0:
        init(0, len(nums) - 1, 1, nums, tree)
    elif oper == 1:
        update(0, len(nums) - 1, 1, b-1, c, tree, nums)
    else:
        S = sum(0, len(nums)-1,1,b-1,c-1,tree)
    return S
def sol():
    n,m,k = map(int,input().split(' '))
    num_list = []
    for _ in range(n):
        num_list.append(int(input()))
    tree = [0]*4*len(num_list)
    seg_tree(num_list, 0,0,0, tree)
 
    for i in range(m+k):
        a,b,c=map(int,input().split(' '))
        S = seg_tree(num_list,a,b,c, tree)
        if S != 0:
            print(S)
 
sol()