hdu 1166 树状数组//线段树

树状数组

#include <iostream>
#include <stdio.h>
#include <string.h>
#define MAX 50005
using namespace std;
int n,c[MAX];
int lowbit(int i)
{
    return i&(-i);
}

int Query(int i)
{
    int sum=0;
    while(i>0)
    {
        sum+=c[i];
        i-=lowbit(i);
    }
    return sum;
}

void update(int i,int val)
{
    while(i<=n)
    {
        c[i]+=val;
        i+=lowbit(i);
    }
}

int main()
{
    freopen("in.txt","r",stdin);
    int t,a;
    char str[10];
    scanf("%d",&t);
    for(int tt=1;tt<=t;tt++)
    {
        memset(c,0,sizeof(c));
        printf("Case %d:\n",tt);
        scanf("%d",&n);
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&a);
            update(i,a);
        }
        while(scanf("%s",str)!=EOF&&strcmp(str,"End")!=0)
        {
            int x,y;scanf("%d%d",&x,&y);
            if(!strcmp(str,"Query"))
            {
                printf("%d\n",Query(y)-Query(x-1));
            }
            if(!strcmp(str,"Add"))
            {
                update(x,y);
            }
            if(!strcmp(str,"Sub"))
            {
                update(x,-y);
            }
        }
    }
    return 0;
}

线段树

#include <iostream>
#include <stdio.h>
#include <string.h>
#define MAX 50005
using namespace std;
int n,d[MAX];
struct node
{
    int l,r,num;
}tree[MAX*3];

int build(int l,int r,int id)
{
    tree[id].l=l;
    tree[id].r=r;
    if(l==r)
    {
        return tree[id].num=d[l];
    }
    int mid=(l+r)/2;
    return tree[id].num=build(l,mid,id<<1)+build(mid+1,r,id<<1|1);
}

int Query(int l,int r,int id)
{
    if(l==tree[id].l&&r==tree[id].r)
    {
        return tree[id].num;
    }
    int mid=(tree[id].l+tree[id].r)/2;
    if(r<=mid)
    {
        return Query(l,r,id<<1);
    }
    else if(mid<l)
    {
        return Query(l,r,id<<1|1);
    }
    else return Query(l,mid,id<<1)+Query(mid+1,r,id<<1|1);
}

void upDate(int i,int x,int id)
{
    tree[id].num+=x;
    if(tree[id].l==tree[id].r)return;
    int mid=(tree[id].l+tree[id].r)/2;
    if(i<=mid)upDate(i,x,id<<1);
    else upDate(i,x,id<<1|1);
}

int main()
{
    //freopen("in.txt","r",stdin);
    int t,a;
    char str[10];
    scanf("%d",&t);
    for(int tt=1;tt<=t;tt++)
    {
        printf("Case %d:\n",tt);
        scanf("%d",&n);
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&d[i]);
        }
        build(1,n,1);
        while(scanf("%s",str)!=EOF&&strcmp(str,"End")!=0)
        {
            int x,y;scanf("%d%d",&x,&y);
            if(!strcmp(str,"Query"))
            {
                printf("%d\n",Query(x,y,1));
            }
            if(!strcmp(str,"Add"))
            {
                upDate(x,y,1);
            }
            if(!strcmp(str,"Sub"))
            {
                upDate(x,-y,1);
            }
        }
    }
    return 0;
}