线段树

来源：互联网发布：校园网络使用代理软件编辑：程序博客网时间：2024/06/06 03:13
poj3468
#include<stdio.h>#include<string.h>long long int tree[444444],lazy[444444];void pushdown(int p,int l,int r){  if(lazy[p])  {    int mid=(l+r)/2;    lazy[2*p]+=lazy[p];    lazy[2*p+1]+=lazy[p];    tree[2*p]+=lazy[p]*(mid-l+1);    tree[2*p+1]+=lazy[p]*(r-mid);    lazy[p]=0;  }}void build(int p,int l,int r){  if(l==r)  {    scanf("%I64d",&tree[p]);    return;  }  int mid=(l+r)/2;  build(2*p,l,mid);  build(2*p+1,mid+1,r);  tree[p]=tree[2*p]+tree[2*p+1];}long long int find(int p,int l,int r,int x,int y){  if(x<=l&&y>=r)    return tree[p];  pushdown(p,l,r);  int mid=(l+r)/2;  long long int sum=0;  if(x<=mid) sum+=find(2*p,l,mid,x,y);  if(y>mid) sum+=find(2*p+1,mid+1,r,x,y);  return sum;}void change(int p,int l,int r,int x,int y,int sum){  if(x<=l&&y>=r)  {    lazy[p]+=sum;    tree[p]+=(long long)sum*(r-l+1);    return;  }  pushdown(p,l,r);  int mid=(l+r)/2;  if(x<=mid) change(2*p,l,mid,x,y,sum);  if(y>mid) change(2*p+1,mid+1,r,x,y,sum);  tree[p]=tree[2*p]+tree[2*p+1];}int main(){  int m,n,x,y,sum;  char s[2];  memset(lazy,0,sizeof(lazy));  memset(tree,0,sizeof(tree));  scanf("%d%d",&n,&m);  build(1,1,n);  while(m--)  {    scanf("%s",s);    if(s[0]=='Q')    {      scanf("%d%d",&x,&y);      printf("%I64d\n",find(1,1,n,x,y));    }    else    {      scanf("%d%d%d",&x,&y,&sum);      change(1,1,n,x,y,sum);    }  }}
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