自用线段树模板

已经没什么好说的了。

#include <iostream>
#include <cstdio>
#include <cstring>
#define maxn 100010
using namespace std;
long long a[maxn];
struct segment_tree{
long long sum[maxn<<2+1];long long add[maxn<<2+1];
#define lson o<<1
#define rson o<<1|1
inline void push_down(int o,int l,int r){
if(!add[o])
return;
add[lson] += add[o];
add[rson] += add[o];
int mid = (l+r) >> 1;
sum[lson] += add[o]*(mid - l + 1);
sum[rson] += add[o]*(r - mid);
add[o] = 0;
}
inline void push_up(int o){
sum[o] = sum[lson] + sum[rson];
}
inline void build(int o,int l,int r){
add[o] = 0;
if(l == r){
sum[o] = a[l];
return;
}
int mid = (l+r) >> 1;
build(lson,l,mid);
build(rson,mid+1,r);
push_up(o);
}
inline long long calc_sum(int o,int l,int r,int ql,int qr){
if(ql <= l && qr >= r)
return sum[o];
int mid = (l+r) >> 1;
push_down(o,l,r);
long long ans = 0;
if(ql <= mid)
ans += calc_sum(lson,l,mid,ql,qr);
if(qr > mid)
ans += calc_sum(rson,mid+1,r,ql,qr);
return ans;
}
inline void update(int o,int l,int r,int ql,int qr,int v){
if(ql <= l && qr >= r){
add[o] += v;
sum[o] += v*(r - l + 1);
return;
}
int mid = (l+r) >> 1;
push_down(o,l,r);
if(ql <= mid)
update(lson,l,mid,ql,qr,v);
if(qr > mid)
update(rson,mid+1,r,ql,qr,v);
push_down(o,l,r);
push_up(o);
}
};
int n,m;
segment_tree tree;
inline int read(){
int num = 0;
char c;
bool flag = false;
while ((c = getchar()) == ' ' || c == '\n' || c == '\r');
if (c == '-')
flag = true;
else
num = c - '0';
while (isdigit(c = getchar()))
num = num * 10 + c - '0';
return (flag ? -1 : 1) * num;
}
int main(){
n = read();m = read();
for(int i=1;i<=n;i++)
a[i] = 1ll*read();
tree.build(1,1,n);
for(int i=1;i<=m;i++){
int opt,x,y;
long long k;
opt = read();
if(opt == 2){
x = read();y = read();
long long int s = tree.calc_sum(1,1,n,x,y);
printf("%lld\n",s);
}
if(opt == 1){
x = read();y = read();k = read();
tree.update(1,1,n,x,y,k);
}
}
return 0;
}