【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);
        }
            
    }
}