1 10 1 2 3 4 5 6 7 8 9 10 Query 1 3 Add 3 6 Query 2 7 Sub 10 2 Add 6 3 Query 3 10 End
Case 1: 6 33 59
树状数组:
#include<stdio.h>
#include<string.h>
#include<math.h>
int a[50005];
int n;
int lowbit(int t)
{
return t&(-t);
}
void insert(int t,int d)
{
while(t<=n)
{
a[t]+=d;
t+=lowbit(t);
}
}
int getsum(int t)
{
int sum=0;
while(t>0)
{
sum+=a[t];
t-=lowbit(t);
}
return sum;
}
int main()
{
int T,i,j,k,t;
scanf("%d",&T);
t=0;
while(T--)
{
memset(a,0,sizeof(a));
scanf("%d",&n);
for(i=1;i<=n;i++)
{
scanf("%d",&k);
insert(i,k);
}
char str[10];
scanf("%s",str);
printf("Case %d:\n",++t);
while(str[0]!='E')
{
int x,y;
scanf("%d%d",&x,&y);
if(str[0]=='Q')
printf("%d\n",getsum(y)-getsum(x-1));
else if(str[0]=='A')
insert(x,y);
else if(str[0]=='S')
insert(x,(-1)*y);
scanf("%s",str);
}
}
return 0;
}
线段树:
#include<iostream>
#include<cstring>]
#include<cstdio>
using namespace std;
struct Node
{
int left,right;
int sum;
}node[4*50005];
int a[50005];
void build(int l,int r,int i)
{
node[i].left=l;
node[i].right=r;
if(l==r)
{
node[i].sum=a[l];
return ;
}
int m=(l+r)/2;
build(l,m,i*2);
build(m+1,r,i*2+1);
node[i].sum=node[i*2].sum+node[i*2+1].sum;
}
void update(int i,int x,int y)
{
int l=node[i].left;
int r=node[i].right;
int m=(l+r)/2;
if(x==l && x==r)
{
node[i].sum += y;
return ;
}
if(x<=m)
update(i*2,x,y);
else
update(i*2+1,x,y);
node[i].sum += y;
}
int query(int l,int r,int i)
{
if(node[i].left==l && node[i].right==r)
return node[i].sum;
//if(node[i].left==node[i].right)
//return 0;
int m=(node[i].left+node[i].right)/2;
if(r<=m)
return query(l,r,i*2);
else if(l>m)
return query(l,r,i*2+1);
else
return query(l,m,i*2)+query(m+1,r,i*2+1);
}
int main()
{
int T;
scanf("%d",&T);
for(int k=1;k<=T;k++)
{
memset(a,0,sizeof(a));
int i,n;
scanf("%d",&n);
for(i=1;i<=n;i++)
scanf("%d",&a[i]);
build(1,n,1);
char str[10];
int x,y;
printf("Case %d:\n",k);
scanf("%s",str);
while(str[0]!='E')
{
scanf("%d%d",&x,&y);
if(str[0]=='Q')
printf("%d\n",query(x,y,1));
else if(str[0]=='A')
update(1,x,y);
else
update(1,x,-y);
scanf("%s",str);
}
}
return 0;
}
原文地址:http://blog.csdn.net/hyccfy/article/details/38397563