[模板] 分块

边角暴力，大块整体，好写的暴力数据结构。

区间查询，单点修改。（树状数组的活）

//Stay foolish,stay hungry,stay young,stay simple
#include<iostream>
#include<cstdio>
#include<cctype>
#include<cmath>
#define R register
using namespace std;

const int MAXN=500005;

int sum[MAXN],r[MAXN],l[MAXN];
int a[MAXN],belong[MAXN],block;
int n,m,num;

inline int read_d(){
    int ret=0,f=1;char c;
    while(c=getchar(),!isdigit(c)) f=c=='-'?-1:1;
    while(isdigit(c)){
        ret*=10;ret+=c-'0';c=getchar();
    }
    return ret*f;
}

inline void write(int x)
{
    if(x<0) x=-x;
    if(x>9) write(x/10);
    putchar(x%10+'0');
}

inline void build(){
    block=sqrt(n);
    num=n/block;
    if(n%block) num++;
    for(R int i=1;i<=num;i++){
        l[i]=(i-1)*block+1;
        r[i]=i*block;
    }
    for(R int i=1;i<=n;i++)
        belong[i]=(i-1)/block+1;
    r[num]=n;
    for(R int i=1;i<=num;i++)
        for(int j=l[i];j<=r[i];j++)
            sum[i]+=a[j];
}

inline void updata(int now,int w){
    a[now]+=w;
    sum[belong[now]]+=w; 
}

inline int query(int x,int y){
    int ret=0;
    if(belong[x]==belong[y]){
        for(R int i=x;i<=y;i++) ret+=a[i];
        return ret;
    }
    for(R int i=x;i<=r[belong[x]];i++) ret+=a[i];
    for(R int i=belong[x]+1;i<=belong[y]-1;i++)
        ret+=sum[i];
    for(R int i=l[belong[y]];i<=y;i++) ret+=a[i];
    return ret;
}

int main(){
    n=read_d();
    m=read_d();

    for(R int i=1;i<=n;i++)
        a[i]=read_d();
    build();
    for(R int i=1;i<=m;i++){
        int x,y,q;
        q=read_d();
        x=read_d();
        y=read_d();
        if(q==1) updata(x,y);
        else write(query(x,y)),putchar('
');
    }
    return 0;
}

区间修改，区间查询。线段树的活，跑得挺快是真的。

//Stay foolish,stay hungry,stay young,stay simple
#pragma GCC optimize(3)
#include<iostream>
#include<cstdio>
#include<cctype>
#include<cmath>

using namespace std;

typedef long long ll;

const int MAXN=500005;

ll sum[MAXN],r[MAXN],l[MAXN],inc[MAXN];
ll a[MAXN],belong[MAXN],block;
ll n,m,num;

inline ll read_d(){
    ll ret=0,f=1;char c;
    while(c=getchar(),!isdigit(c)) f=c=='-'?-1:1;
    while(isdigit(c)){
        ret*=10;ret+=c-'0';c=getchar();
    }
    return ret*f;
}

inline void write(ll x)
{
    if(x<0) x=-x;
    if(x>9) write(x/10);
    putchar(x%10+'0');
}

inline void build(){
    block=sqrt(n);
    num=n/block;
    if(n%block) num++;
    for(int i=1;i<=num;i++){
        l[i]=(i-1)*block+1;
        r[i]=i*block;
    }
    for(int i=1;i<=n;i++)
        belong[i]=(i-1)/block+1;
    r[num]=n;
    for(int i=1;i<=num;i++)
        for(int j=l[i];j<=r[i];j++)
            sum[i]+=a[j];
}

//inline void updata(int now,int w){
//    a[now]+=w;
//    sum[belong[now]]+=w; 
//}

inline void updata(ll x,ll y,ll w){
    if(belong[x]==belong[y]){
        for(int i=x;i<=y;i++) a[i]+=w;
        sum[belong[x]]+=w*(y-x+1);
        return ;
    }
    for(int i=x;i<=r[belong[x]];i++)
        a[i]+=w,sum[belong[i]]+=w;
    for(int i=belong[x]+1;i<=belong[y]-1;i++)
        inc[i]+=w;
    for(int i=l[belong[y]];i<=y;i++)
        a[i]+=w,sum[belong[i]]+=w;
//  sum[belong[y]]+=w*(y-l[belong[y]]+1);
}

inline ll query(int x,int y){
    ll ret=0;
    if(belong[x]==belong[y]){
        for(int i=x;i<=y;i++) ret+=a[i]+inc[belong[i]];
        return ret;
    }
    for(int i=x;i<=r[belong[x]];i++) ret+=a[i]+inc[belong[i]];
    for(int i=belong[x]+1;i<=belong[y]-1;i++)
        ret+=sum[i]+inc[i]*(r[i]-l[i]+1);
    for(int i=l[belong[y]];i<=y;i++) ret+=a[i]+inc[belong[i]];
//    if(belong[x]==belong[y]){
//      ret-=a[x]+2*inc[belong[x]]+a[y];
//  }
    return ret;
}

int main(){
    n=read_d();
    m=read_d();
    for(int i=1;i<=n;i++)
        a[i]=read_d(); 
    build();
    for(int i=1;i<=m;i++){
        ll q,x,y,z;
        q=read_d();
        x=read_d();
        y=read_d();
        if(q==1) z=read_d(),updata(x,y,z);
        else write(query(x,y)),putchar('
');
    }
    return 0;
}