Complexity?

// water = tree<int,null_type,less<int>rb_tree_tag,tree_order_statistics_node_update>
int l = pos, r = water.size(), lb, rb;
while (l + 1 < r) {
    int m = (l + r) >> 1;
    if (*(water.fbo(m)) - x > m - pos) r = m;
    else l = m;
}
if (*(water.fbo(r)) - x == r - pos) rb = x + r - pos;
else rb = x + l - pos;
l = 0, r = pos;
while (l + 1 < r) {
    int m = (l + r) >> 1;
    if (x - *(water.fbo(m)) > pos - m) l = m;
    else r = m;
}
if (x - *(water.fbo(l)) == pos - l) lb = x - pos + l;
else lb = x - pos + r;
water.erase(rb - (x - lb));
water.insert(lb - 1);
water.insert(rb + 1);