【模板】zkw线段树

题意简述

已知一个数列，你需要进行下面两种操作：

1.将某一个数加上x

2.求出某区间每一个数的和

代码

#include <cstdio>
using namespace std;
int n, m, N;
int a[1200001];
int main()
{
	scanf("%d%d", &n, &m);
	for (N = 1; N < n + 2; N <<= 1);
	for (register int i = 1; i <= n; ++i)
		scanf("%d", &a[i + N]);
	for (register int i = N; --i; )
		a[i] = a[i << 1] + a[i << 1 | 1];
	for (register int i = 1; i <= m; ++i)
	{
		int opt, x, y, ans = 0;
		scanf("%d%d%d", &opt, &x, &y);
		if (opt == 1) for (register int j = x + N; j; j >>= 1) a[j] += y;
		if (opt == 2)
		{
			for (register int j = x + N - 1, k = y + N + 1; j ^ k ^ 1; j >>= 1, k >>= 1)
			{
				if (~j & 1)	ans += a[j ^ 1];
				if ( k & 1)	ans += a[k ^ 1];
			}
			printf("%d\n", ans);
		}

	}
}