@[dpACerLZJun](/user/549846)
```
# include<iostream>
# include<algorithm>
# include<cmath>
# define int long long
# define endl "\n"
using namespace std;
const int maxn=1e6+1, INF=2147386547;
int n, m, a[maxn];
struct Node{
int l, r, mmax;
int add, change;
}tree[maxn*4];
void build_tree(int i, int l, int r) {
tree[i].l=l; tree[i].r=r; tree[i].mmax=-INF; tree[i].change=INF;
if(l==r) {
tree[i].mmax=a[l];
return ;
}
int mid=(l+r)/2;
build_tree(2*i, l, mid);
build_tree(2*i+1, mid+1, r);
tree[i].mmax=max(tree[2*i].mmax, tree[2*i+1].mmax);
}
void push_down(int i) {
if(tree[i].change!=INF) {
tree[i*2].mmax=tree[i*2+1].mmax=tree[i].change+tree[i].add;
tree[i*2].change=tree[i*2+1].change=tree[i].change;
tree[i*2].add=tree[i*2+1].add=tree[i].add;
} else {
tree[i*2].mmax+=tree[i].add;
tree[i*2+1].mmax+=tree[i].add;
tree[i*2].add+=tree[i].add;
tree[i*2+1].add+=tree[i].add;
}
tree[i].change=INF;
tree[i].add=0;
}
void add(int i, int l, int r, int d) {
if(tree[i].l>=l && tree[i].r<=r) {
tree[i].mmax+=d;
tree[i].add+=d;
return ;
}
push_down(i);
int mid=(tree[i].l+tree[i].r)/2;
if(l<=mid) add(2*i, l, r, d);
if(r>=mid+1) add(2*i+1, l, r, d);
tree[i].mmax=max(tree[2*i].mmax, tree[2*i+1].mmax);
}
void change(int i, int l, int r, int d) {
if(tree[i].l>=l && tree[i].r<=r) {
tree[i].mmax=d;
tree[i].add=0;
tree[i].change=d;
return ;
}
push_down(i);
int mid=(tree[i].l+tree[i].r)/2;
if(l<=mid) change(2*i, l, r, d);
if(r>=mid+1) change(2*i+1, l, r, d);
tree[i].mmax=max(tree[2*i].mmax, tree[2*i+1].mmax);
}
int query(int i, int l, int r) {
if(tree[i].l>=l && tree[i].r<=r) return tree[i].mmax;
push_down(i);
int mid=(tree[i].l+tree[i].r)/2, mmax=-1e18;
if(l<=mid) mmax=max(mmax, query(2*i, l, r));
if(r>=mid+1) mmax=max(mmax, query(2*i+1, l, r));
return mmax;
}
signed main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> m;
for(int i=1; i<=n; i++) cin >> a[i];
build_tree(1, 1, n);
while(m--) {
int op; cin >> op;
if(op==1) {
int x, y, k; cin >> x >> y >> k;
change(1, x, y, k);
} else if(op==2) {
int x, y, k; cin >> x >> y >> k;
add(1, x, y, k);
} else {
int x, y; cin >> x >> y;
cout << query(1, x, y) << endl;
}
}
return 0;
}
```
问题1：第28行应赋值为 `tree[x].add`
问题2：第66行 `mmax` 的值应该更小，因为答案可能是负数
问题3：请使用较快的输入输出方式
\\\\\\改了之后应该能过
by FlyPancake @ 2024-04-13 16:09:29
6
by jmjy1928 @ 2024-04-13 21:21:52
@[FlyPancake](/user/819577) 谢谢大佬 已AC
by dpACerLZJun @ 2024-04-14 08:52:32
给了4个关注
by dpACerLZJun @ 2024-04-14 08:54:49