algorithm/segment_tree(lazy).cpp at main · ihbadhon/algorithm · GitHub

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ll arr[10000];
struct info
{
    ll prop, sum;
} tree[10000*4];

void init(int node, int b, int e) {
    if(b==e) {
        tree[node].sum = arr[b];
        return;
    }

    int mid = b + (e-b)/2;
    init(node*2, b, mid);
    init(node*2+1, mid+1, e);
    tree[node].sum = tree[node*2].sum + tree[node*2+1].sum;
}

void update(int node, int b, int e, int i, int j, ll x) {
    if(i>e or j<b)
    return;
    if(b>=i and e<=j){
        tree[node].sum += ((e-b+1)*x);
        tree[node].prop += x;
        return;
    }

    int mid = b + (e-b)/2;
    update(node*2, b, mid, i, j, x);
    update(node*2+1, mid+1, e, i, j, x);

    tree[node].sum = tree[node*2].sum + tree[node*2+1].sum + (e-b+1)*tree[node].prop;
}

ll query(int node, int b, int e, int i, int j, ll carry = 0){
    if(i>e or j<b)
    return 0;
    if(b>=i and e<=j)
    {
        return tree[node].sum + carry * (e-b+1);
    }

    int mid = (b+e) >> 1;

    ll p1 = query(node*2, b, mid, i, j, carry+tree[node].prop);
    ll p2 = query(node*2+1, mid+1, e, i, j, carry+tree[node].prop);
    return p1 + p2;
}