线段树区间查询区间修改函数

#define lson (rt<<1)
#define rson (rt<<1|1)
const int maxn=1e6+10;
int n,m;
struct node
{int l,r;long long sum;int lazy;
}tree[maxn<<2];
int a[maxn];
void pushdown(int rt)
{if (tree[rt].lazy){int lazy=tree[rt].lazy;tree[rt].lazy=0;tree[lson].lazy += lazy;tree[rson].lazy += lazy;tree[lson].sum += lazy*(tree[lson].r-tree[lson].l+1);tree[rson].sum += lazy*(tree[rson].r-tree[rson].l+1);}
}
void pushup(int rt)
{tree[rt].sum = tree[lson].sum+tree[rson].sum;
}
void build(int rt,int l,int r)
{tree[rt].l=l;tree[rt].r=r;if (l == r){tree[rt].sum=a[l];return;}int mid=(l+r) >> 1;build(lson,l,mid);build(rson,mid+1,r);pushup(rt);
}
void update(int rt,int l,int r,int val)
{if (l<=tree[rt].l && tree[rt].r<=r){tree[rt].lazy += val;tree[rt].sum += val*(tree[rt].r-tree[rt].l+1);return;}pushdown(rt);int mid = (tree[rt].l+tree[rt].r) >> 1;if (l <= mid) update(lson,l,r,val);if (r > mid) update(rson,l,r,val);pushup(rt);
}
long long query(int rt,int l,int r)
{if (l<=tree[rt].l && tree[rt].r<=r){return tree[rt].sum;}pushdown(rt);int mid = (tree[rt].l + tree[rt].r) >> 1;if (r<=mid) return query(lson,l,r);else if (l>mid) return query(rson,l,r);else return query(lson,l,r)+query(rson,l,r);
}