洛谷p3372 线段树2
题意:区间操作中混合了加减操作跟乘操作
思路:只要设计出不同操作之间协作的方式(propagate),区间合并的方式即可
总结:Node重载+中,返回值mod括号位置加错了。
mul应该初始化为1,初始化错了。
少见的线段树第一次提交直接ac。
int MOD;
struct lazyNode{
long long add;
long long mul;
bool is_lazy;
lazyNode(long long add_, long long mul_):add(add_), mul(mul_), is_lazy(true){}
lazyNode():is_lazy(false), add(0ll), mul(1ll){}
void operator |= (const lazyNode& other){
if (this->is_lazy == false){
this->add = other.add;
this->mul = other.mul;
this->is_lazy = true;
}
else{
this->add = ((this->add) * other.mul % MOD + other.add) % MOD;
this->mul = (this->mul * other.mul % MOD);
}
}
bool operator != (const lazyNode& other){
return this->is_lazy != other.is_lazy;
}
};
struct Node{
long long sum;
Node():sum(0ll){}
Node(long long value): sum(value){}
Node operator +(const Node& other){
return Node((this->sum + other.sum) % MOD);
};
void applyLazy(lazyNode& value, int length){
this->sum = ((this->sum * value.mul) % MOD + value.add * length % MOD) % MOD;
}
};
template<typename T, typename U>
class SegmentTree{
public:
SegmentTree(const vector<T>& s): sz_(int(s.size() - 1)){
st_.resize(4 * sz_);
lazy_.resize(4 * sz_);
build(s, 1, 1, sz_);
}
void update(int i, int j, lazyNode value){
update(1, 1, sz_, i, j, value);
}
long long query(int i, int j){
return query(1, 1, sz_, i, j).sum;
}
private:
vector<T> st_;
vector<U> lazy_;
int sz_;
const U flag_{};
void update(int p, int l, int r, int i, int j, lazyNode value){
propagate(p, l, r);
if (i > j){
return;
}
if (l >= i && r <= j){
lazy_[p] = value;
propagate(p, l, r);
return;
}
int mid = (l + r) >> 1;
update(p << 1, l, mid, i, min(mid, j), value);
update(p << 1 | 1, mid + 1, r, max(mid + 1, i), j, value);
st_[p] = st_[p << 1] + st_[p << 1 | 1];
};
T query(int p, int l, int r, int i, int j){
propagate(p, l, r);
if (l >= i && r <= j){
return st_[p];
}
int mid = (l + r) >> 1;
if (j <= mid) {
return query(p << 1, l, mid, i, j);
}
else if (i > mid) {
return query(p << 1 | 1, mid + 1, r, i, j);
}
else {
return (query(p << 1, l, mid, i, mid) + query(p << 1 | 1, mid + 1, r, mid + 1, j));
}
}
void build(const vector<T>& s, int p, int l, int r){
if (l == r){
st_[p] = s[l];
}
else{
int mid = (l + r) >> 1;
build(s, p << 1, l, mid);
build(s, p << 1 | 1, mid + 1, r);
st_[p] = st_[p << 1] + st_[p << 1 | 1];
}
}
void propagate(int p, int l, int r){
if (lazy_[p] != flag_){
st_[p].applyLazy(lazy_[p], r - l + 1);
if (l != r){
lazy_[p << 1] |= lazy_[p];
lazy_[p << 1 | 1] |= lazy_[p];
}
lazy_[p] = flag_;
}
}
};
void solve(){
int n, m;
cin >> n >> m >> MOD;
vector<Node> a(n + 1);
for (int i = 1; i <= n; ++i){
cin >> a[i].sum;
}
SegmentTree<Node, lazyNode> st(a);
while (m --){
int k, x, y;
cin >> k >> x >> y;
if (k == 1){
long long v;
cin >> v;
st.update(x, y, lazyNode(0ll, v));
}
else if (k == 2){
long long v;
cin >> v;
st.update(x, y, lazyNode(v, 1ll));
}
else{
cout << st.query(x, y) << '\n';
}
}
}

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