模板 - 线段树

线段树还需要模板的菜鸡

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define lt ls, l, m
#define rt rs, m + 1, r
#define ls (o<<1)
#define rs (o<<1|1)

const int MAXM = 100000 + 5;
ll a[MAXM];
ll st[MAXM * 4], lazy[MAXM * 4];

inline void PushUp(int o) {
    st[o] = st[ls] + st[rs];
}

inline void PushDown(int o, int l, int r) {
    if(lazy[o]) {
        lazy[ls] += lazy[o];
        lazy[rs] += lazy[o];
        int m = l + r >> 1;
        st[ls] += lazy[o] * (m - l + 1);
        st[rs] += lazy[o] * (r - m);
        lazy[o] = 0;
    }
}

void Build(int o, int l, int r) {
    if(l == r)
        st[o] = a[l];
    else {
        int m = l + r >> 1;
        Build(lt);
        Build(rt);
        PushUp(o);
    }
    lazy[o] = 0;
}

void Update(int o, int l, int r, int ql, int qr, ll v) {
    if(ql <= l && r <= qr) {
        lazy[o] += v;
        st[o] += v * (r - l + 1);
        return;
    } else {
        PushDown(o, l, r);
        int m = l + r >> 1;
        if(ql <= m)
            Update(lt, ql, qr, v);
        if(qr >= m + 1)
            Update(rt, ql, qr, v);
        PushUp(o);
    }
}

ll Query(int o, int l, int r, int ql, int qr) {
    if(ql <= l && r <= qr) {
        return st[o];
    } else {
        PushDown(o, l, r);
        int m = l + r >> 1;
        ll res = 0;
        if(ql <= m)
            res = res + Query(lt, ql, qr);
        if(qr >= m + 1)
            res = res + Query(rt, ql, qr);
        return res;
    }
}

int main() {
#ifdef Yinku
    freopen("Yinku.in", "r", stdin);
#endif // Yinku
    int n, m;
    scanf("%d%d", &n, &m);
    for(int i = 1; i <= n; ++i) {
        scanf("%d", &a[i]);
    }
    Build(1,1,n);
    int op, x, y, k;
    while(m--) {
        scanf("%d%d%d", &op, &x, &y);
        if(op == 1) {
            scanf("%d", &k);
            Update(1, 1, n, x, y, k);
        } else {
            printf("%lld\n", Query(1, 1, n, x, y));
        }
    }
    return 0;
}

来源：https://www.cnblogs.com/Inko/p/11404072.html