[Code] Detailed ultra LOJ # 132 Fenwick tree 3: Modify the interval, the interval query

One, Title Description

Sample

Sample input

5 10
2 6 6 1 1
2 1 4
1 2 5 10
2 1 3
2 2 3
1 2 2 8
1 2 3 7
1 4 4 10
2 1 2
1 4 5 6
2 3 4

Sample Output

15
34
32
33
50

Second, the algorithm analysis and writing code instructions guide

If you do not understand Fenwick tree, recommended solution to a problem before the first reading:
https://blog.csdn.net/COFACTOR/article/details/104199313
https://blog.csdn.net/COFACTOR/article/details/104206182
b [ i] + = i * d + I = a write start = not calculated and d = arr [i] - arr [i - 1] but is written directly to the right of i * a [i] in the sample card which led me for a long time, relying on.

Three, AC codes

#include<cstdio>
#pragma warning(disable:4996)
template<class _Ty> class Binary_Index_Tree_D {
private:
	_Ty* a, * b; size_t n;
	size_t lowbit(const size_t& x) const { return x & (~x + 1); }
	_Ty at_b(size_t N) const {
		_Ty sum = 0;
		while (N) { sum += b[N], N -= lowbit(N); }
		return sum;
	}
public:
	Binary_Index_Tree_D(const size_t& Size) {
		a = new _Ty[Size + 2](), b = new _Ty[Size + 2](), n = Size;
	}
	Binary_Index_Tree_D(const _Ty* arr, const size_t& Size) {
		a = new _Ty[Size + 2](), b = new _Ty[Size + 2](), n = Size; _Ty d;
		for (size_t i = 1, j; i <= n; ++i) {
			d = arr[i] - arr[i - 1], a[i] += d, b[i] += i * d, j = i + lowbit(i);
			if (j <= n) { a[j] += a[i]; b[j] += b[i]; }
		}
	}
	~Binary_Index_Tree_D() { delete[] a; delete[] b; }
	void add(size_t pos, const _Ty& val) {
		_Ty val1 = pos * val;
		while (pos <= n) { a[pos] += val, b[pos] += val1, pos += lowbit(pos); }
	}
	_Ty at(size_t N) const {
		_Ty sum = 0;
		while (N) { sum += a[N], N -= lowbit(N); }
		return sum;
	}
	_Ty prefix_sum(const size_t& N) const { return (N + 1) * at(N) - at_b(N); }
	void range_add(const size_t& L, const size_t& R, const _Ty& val) {
		add(L, val), subtract(R + 1, val);
	}
	void range_subtract(const size_t& L, const size_t& R, const _Ty& val) {
		subtract(L, val), add(R + 1, val);
	}
	_Ty range_sum(const size_t& L, const size_t& R) const { return prefix_sum(R) - prefix_sum(L - 1); }
	size_t size() const { return n; }
	void subtract(size_t pos, const _Ty& val) {
		_Ty val1 = pos * val;
		while (pos <= n) { a[pos] -= val, b[pos] -= val1, pos += lowbit(pos); }
	}
};
unsigned m, q; unsigned long long n, l, r; long long a[1000002], x;
int main() {
	scanf("%llu%u", &n, &q); ++q;
	for (unsigned long long i = 1; i <= n; ++i) { scanf("%lld", &a[i]); }
	static Binary_Index_Tree_D<long long> b(a, n);
	while (--q) {
		scanf("%u", &m);
		switch (m) {
		case 1:
			scanf("%llu%llu%lld", &l, &r, &x); b.range_add(l, r, x);
			continue;
		default:
			scanf("%llu%llu", &l, &r); printf("%lld\n", b.range_sum(l, r));
		}
	}
	return 0;
}