Segment Tree

void upd(int v, int l, int r, int idx, int val) {
    if (l == r) {
        A[idx] = val;
        tree[v] = val;
        return;
    }
    int mid = (l + r) / 2;
    if (l <= idx && idx <= mid)
        upd(2 * v, l, mid, idx, val);
    else upd(2 * v + 1 , mid + 1, r, idx, val);
    tree[v] = min(tree[2 * v], tree[2 * v + 1]);
}

void build(int v, int l, int r) {
    if (l == r) {
        tree[v] = A[l];
        return;
    }
    int mid = (l + r) / 2;
    build(2 * v, l, mid);
    build(2 * v + 1, mid + 1, r);
    tree[v] = min(tree[2 * v], tree[2 * v + 1]);
}

int query(int v, int l, int r, int L, int R) {
    if (R < l || r < L)
        return INF;
    if (L <= l && r <= R)
        return tree[v];
    int mid = (l + r) / 2;
    int p1 = query(2 * v, l, mid, L, R);
    int p2 = query(2 * v + 1, mid + 1, r, L, R);
    return min(p1, p2);
}