C++(씨쁠쁠)(cplusplus)-백준(baekjoon)(BaekJoon)코딩 10999번:구간 합 구하기 2 답

#include <iostream>
#include <cmath>
#include <vector>
using namespace std;
//ary :입력받는 배열
//tree : 새그먼트 트리
//node : 트리의 노드 번호
//start~end까지의 구간의 합 구하기.
long long init(vector<long long> &ary, vector<long long> &tree,int node,int start,int end)
{
    if (start == end)
        return tree[node] = ary[start];
    else
        return tree[node] = init(ary, tree, node * 2, start, (start + end) / 2) + init(ary, tree, node * 2 + 1, (start + end) / 2 + 1, end);
}
void update_lazy(vector<long long> &tree, vector <long long> &lazy, int node, int start, int end)
{
    if (lazy[node] != 0)
    {
        tree[node] += (end - start + 1) * lazy[node];
        //leaf node가 아니면
        if (start != end)
        {
            lazy[node * 2] += lazy[node];
            lazy[node * 2 + 1] += lazy[node];
        }
        lazy[node] = 0;
    }
}
void update_range(vector<long long> &tree, vector <long long> &lazy, int node, int start, int end, int left, int right, long long diff)
{
    update_lazy(tree, lazy, node, start, end);
    if (left > end || right < start)
        return;
    if (left <= start && right >= end)
    {
        tree[node] += (end - start + 1)*diff;
        if (start != end)
        {
            lazy[node * 2] += diff;
            lazy[node * 2 + 1] += diff;
        }
        return;
    }
    update_range(tree, lazy, node * 2, start, (start + end) / 2, left, right, diff);
    update_range(tree, lazy, node * 2 + 1, (start + end) / 2 + 1, end, left, right, diff);
    tree[node] = tree[node * 2] + tree[node * 2 + 1];
}
long long sum(vector <long long>&tree, vector <long long>&lazy, int node, int start, int end, int left, int right)
{
    update_lazy(tree, lazy, node, start, end);
    if (left>end || right<start)
        return 0;
    if (left <= start && right >= end)
        return tree[node];
    return sum(tree, lazy, node * 2, start, (start + end)/2, left, right) + sum(tree, lazy, node * 2 + 1, (start + end) / 2 + 1, end, left, right);
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n, m, k, a;
    cin >> n >> m >> k;
    vector <long long> ary(n);
    int h = (int)ceil(log2(n));//트리의 높이는 log2(n)
    int tree_size = (1 << (h + 1)) - 1;
    vector <long long> lazy(tree_size);
    vector <long long> tree(tree_size);
    for (int i = 0; i < n; i++)
        cin >> ary[i];
    init(ary, tree, 1, 0, n - 1);
    m += k;
    while (m--)
    {
        int start, end;
        long long diff;
        cin >> a;
        if (a == 1)
        {
            cin >> start >> end >> diff;
            update_range(tree, lazy, 1, 0, n - 1, start-1, end-1, diff);
        }
        else if(a == 2)
        {
            cin >> start >> end;
            cout << sum(tree, lazy, 1, 0, n - 1, start - 1, end - 1) <<'\n';
        }
    }
}