NOI2012魔幻棋盘弱化版

　　gcd(a,b,c,d,e)=gcd(a,b-a,c-b,d-c,e-d)

　　然后就可以把区间修改变成差分后的点修了。

　　用BIT维护原序列，线段树维护区间gcd，支持点修区查

#include
      
       #include
       
        #include
        
         #include
         
          #define ll long longusing namespace std;const int maxn=500010;struct poi{
    int sum;}tree[maxn<<2];int n,m,ty,x,y,z,ans;int a[maxn],bit[maxn];void read(int &k){    int f=1;k=0;char c=getchar();    while(c<'0'||c>'9')c=='-'&&(f=-1),c=getchar();    while(c<='9'&&c>='0')k=k*10+c-'0',c=getchar();    k*=f;}inline int gcd(int a,int b){
    return b?gcd(b,a%b):a;}inline int lowbit(int x){
    return x&-x;}inline void add(int x,int delta){
    for(;x<=n;x+=lowbit(x))bit[x]+=delta;}inline int querybit(int x){
    int sum=0;for(;x;x-=lowbit(x))sum+=bit[x];return sum;}inline void pushup(int x){tree[x].sum=gcd(tree[x<<1].sum,tree[x<<1|1].sum);}void build(int x,int l,int r){    if(l==r){tree[x].sum=a[l]-a[l-1];return;}    int mid=(l+r)>>1;    build(x<<1,l,mid);build(x<<1|1,mid+1,r);    pushup(x);}void update(int x,int l,int r,int cx,int delta){    if(l==r){tree[x].sum+=delta;return;}    int mid=(l+r)>>1;    if(cx<=mid)update(x<<1,l,mid,cx,delta);    else update(x<<1|1,mid+1,r,cx,delta);    pushup(x);}void query(int x,int l,int r,int cl,int cr){    if(cl<=l&&r<=cr){ans=gcd(ans,abs(tree[x].sum));return;}    int mid=(l+r)>>1;    if(cl<=mid)query(x<<1,l,mid,cl,cr);    if(cr>mid)query(x<<1|1,mid+1,r,cl,cr);}int main(){    read(n);read(m);    for(int i=1;i<=n;i++)read(a[i]),add(i,a[i]),add(i+1,-a[i]);    build(1,1,n);    for(int i=1;i<=m;i++)    {        read(ty);read(x);read(y);        if(ty==1)ans=querybit(x),query(1,1,n,x+1,y),printf("%d\n",ans);        else        {            read(z);add(x,z);add(y+1,-z);            update(1,1,n,x,z);update(1,1,n,y+1,-z);        }    }}