洛谷3372 线段树1

//注意求和要*区间个数#include<bits/stdc++.h>using namespace std;const int maxn = 100010;int n, m;long long a[maxn];struct node{    long long val, mark;} segtree[4*maxn];inline void make_tree(int root, int l, int r){    segtree[root].mark = 0;    if(l == r){        segtree[root].val = a[l];        return;    }    int mid = l+r >> 1;    make_tree(root*2, l, mid);    make_tree(root*2+1, mid+1, r);    segtree[root].val = segtree[root*2].val + segtree[root*2+1].val;}inline void pushdown(int root, int l, int r){    if(segtree[root].mark){        int mid = l+r >> 1;        segtree[2*root].mark += segtree[root].mark;        segtree[2*root+1].mark += segtree[root].mark;        segtree[2*root].val += segtree[root].mark * (mid-l+1);        segtree[2*root+1].val += segtree[root].mark * (r-mid);        segtree[root].mark = 0;    }}inline void update(int root, int nl, int nr, int l, int r, int k){    if(nl > r || nr < l)    return;    if(nl >= l && nr <= r){        segtree[root].mark += k;        segtree[root].val += (nr-nl+1) * k;        return;    }    pushdown(root, nl, nr);    int mid = nl+nr >> 1;    update(root*2, nl, mid, l, r, k);    update(root*2+1, mid+1, nr, l, r, k);    segtree[root].val = segtree[2*root].val + segtree[2*root+1].val;}inline long long get_sum(int root, int nl, int nr, int l, int r){    long long ans = 0;    //if(nl > r || nr < l)    return 0;    //if(nl == nr)    return segtree[root].val;    if(nl >= l && nr <= r)    return segtree[root].val;    pushdown(root, nl, nr);    int mid = nl+nr >> 1;    if(mid < r)    ans += get_sum(root*2+1, mid+1, nr, l, r);    if(mid >= l)    ans += get_sum(root*2, nl, mid, l, r);    return ans;}int main(){    scanf("%d%d", &n, &m);    for(int i = 1; i <= n; i++)        scanf("%d", &a[i]);    make_tree(1, 1, n);    for(int i = 1, op, x, y, k; i <= m; i++){        scanf("%d", &op);        if(op == 1){            scanf("%d%d%d", &x, &y, &k);            update(1, 1, n, x, y, k);        }        else if(op == 2){            scanf("%d%d", &x, &y);            long long sum = get_sum(1, 1, n, x, y);            //printf("%lld\n", segtree[1].val);            printf("%lld\n", sum);        }    }    return 0;}