#1 #2 #4 #5 AC，其余 WA，样例二也过不了。

代码：

#include <iostream>
#define ll long long
using namespace std;
const int maxn = 1000001;
ll lzy1[maxn * 4], lzy2[maxn * 4], tree[maxn * 4];
int arr[maxn];
void make_tag1(int u, int len, int x) {
	lzy1[u] = x;
	lzy2[u] = 0;
	tree[u] = x;
}
void make_tag2(int u, int len, int x) {
	lzy2[u] += x;
	tree[u] += x;
}
void pushdown(int u, int L, int R) {
	int m = (L + R) / 2;
	if (lzy1[u]) {
		make_tag1(u * 2, m - L + 1, lzy1[u]);
		make_tag1(u * 2 + 1, R - m, lzy1[u]);
	}else {
		make_tag2(u * 2, m - L + 1, lzy2[u]);
		make_tag2(u * 2 + 1, R - m, lzy2[u]);
	}
	lzy1[u] = lzy2[u] = 0;
}
bool inRange(int L, int R, int l, int r) {
	return l <= L && R <= r;
}
bool outofRange(int L, int R, int l, int r) {
	return R < l || L > r;
}
ll query(int u, int L, int R, int l, int r) {
	if (inRange(L, R, l, r)) return tree[u];
	else if (!outofRange(L, R, l, r)) {
		int m = (L + R) / 2;
		pushdown(u, L, R);
		return max(query(u * 2, L, m, l, r), query(u * 2 + 1, m + 1, R, l, r));
	}else return 0;
}
void pushup(int u) {
	tree[u] = max(tree[u * 2], tree[u * 2 + 1]);
}
void updata1(int u, int L, int R, int l, int r, int x) {
	if (inRange(L, R, l, r)) make_tag1(u, R - L + 1, x);
	else if (!outofRange(L, R, l, r)) {
		int m = (L + R) / 2;
		pushdown(u, L, R);
		updata1(u * 2, L, m, l, r, x);
		updata1(u * 2 + 1, m + 1, R, l, r, x);
		pushup(u);
	}else return;
}
void updata2(int u, int L, int R, int l, int r, ll x) {
	if (inRange(L, R, l, r)) make_tag2(u, R - L + 1, x);
	else if (!outofRange(L, R, l, r)) {
		int m = (L + R) / 2;
		pushdown(u, L, R);
		updata2(u * 2, L, m, l, r, x);
		updata2(u * 2 + 1, m + 1, R, l, r, x);
		pushup(u);
	}else return;
}
void build(int u, int L, int R) {
	if (L == R) {
		tree[u] = arr[L];
		return;
	}
	int m = (L + R) / 2;
	build(u * 2, L, m);
	build(u * 2 + 1, m + 1, R);
	pushup(u);
}
signed main() {
	ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
	int n, m;
	cin >> n >> m;
	for (int i = 1; i <= n; ++i) cin >> arr[i];
	build(1, 1, n);
	while (m--) {
		int op, x, y;
		cin >> op >> x >> y;
		if (op == 1) {
			int k;
			cin >> k;
			updata1(1, 1, n, x, y, k);
		}else if (op == 2) {
			ll k;
			cin >> k;
			updata2(1, 1, n, x, y, k);
		}else cout << query(1, 1, n, x, y) << "\n";
	}
	return 0;
}