线段树 （lazy完全版）

#include <bits/stdc++.h>

using namespace std;
#define ll long long
#define mem(a, b) memset(a,b,sizeof(a))
#define INF 0x3f3f3f3f
#define DBG printf("this is a input\n")
#define fi first
#define se second
#define mk(a, b) make_pair(a,b)
#define p_queue priority_queue

ll gcd(ll a, ll b) {
    return b == 0 ? a : gcd(b, a % b);
}

ll lcm(ll a, ll b) {
    return a / gcd(a, b) * b;
}
struct node
{
    int l , r;
    ll sum , lz;
}tree[2000000];
ll n , m, input[100005];
void pushdown(int i)
{
    if(tree[i].lz != 0)
    {
        tree[i*2].lz += tree[i].lz;
        tree[i*2+1].lz += tree[i].lz;
        int mid = (tree[i].l+tree[i].r)/2;
        tree[i*2].sum += tree[i].lz*(mid - tree[i*2].l + 1);
        tree[i*2+1].sum += tree[i].lz*(tree[i*2+1].r - mid);
        tree[i].lz = 0;
    }
    return ;
}
void build(int i , int l , int r)
{
    tree[i].l = l , tree[i].r = r, tree[i].lz = 0, tree[i].sum = 0;
    if(l == r)
    {
        tree[i].sum = input[l];
        return ;
    }
    int mid = (l+r)/2;
    build(i*2,l,mid);
    build(i*2+1,mid+1,r);
    tree[i].sum = tree[i*2].sum + tree[i*2+1].sum;
}
void add(int i ,int l ,int r ,int k)
{
    if(tree[i].l >= l && tree[i].r <= r)
    {
        tree[i].sum += (tree[i].r-tree[i].l+1)*k;
        tree[i].lz += k;
        return ;
    }
    pushdown(i);
    if(l <= tree[i*2].r)
        add(i*2,l,r,k);
    if(tree[i*2+1].l <= r)
        add(i*2+1,l,r,k);
    tree[i].sum = tree[i*2].sum + tree[i*2+1].sum;
    return ;
}
ll search(int i , int l , int r)
{
    if(tree[i].l >= l && tree[i].r <= r)
        return tree[i].sum;
    if(l > tree[i].r || r < tree[i].l)
        return 0;
    pushdown(i);
    ll ans = 0;
    if(tree[i*2].r >= l)
        ans += search(i*2,l,r);
    if(tree[i*2+1].l <= r)
        ans += search(i*2+1,l,r);
    return ans;
}
int main(void)
{
    scanf("%d %d",&n ,&m);
    for(int i = 1 ; i <= n ; i ++)
        scanf("%d",&input[i]);
    build(1,1,n);
    for(int i = 1 ; i <= m ; i ++)
    {
        int p;
        scanf("%d",&p);
        if(p == 1)
        {
            int x , y, k;
            scanf("%d %d %d",&x,&y,&k);
            add(1,x,y,k);
        }
        else
        {
            int x, y;
            scanf("%d %d",&x,&y);
            printf("%lld\n",search(1,x,y));
        }
    }
}

 

来源：CSDN

作者：Zenith_Habitant

链接：https://blog.csdn.net/Zenith_Habitant/article/details/104444996