FZU Problem 2171 防守阵地 II (线段树区间更新模板题)

#include <iostream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <cstring>
#include <string>
#include <algorithm>
#include <string>
#include <set>
#include <functional>
#include <numeric>
#include <sstream>
#include <stack>
#include <map>
#include <queue>
#pragma comment(linker, "/STACK:102400000,102400000")
#define CL(arr, val)    memset(arr, val, sizeof(arr))

#define ll long long
#define inf 0x7f7f7f7f
#define lc l,m,rt<<1
#define rc m + 1,r,rt<<1|1
#define pi acos(-1.0)

#define L(x)    (x) << 1
#define R(x)    (x) << 1 | 1
#define MID(l, r)   (l + r) >> 1
#define Min(x, y)   (x) < (y) ? (x) : (y)
#define Max(x, y)   (x) < (y) ? (y) : (x)
#define E(x)        (1 << (x))
#define iabs(x)     (x) < 0 ? -(x) : (x)
#define OUT(x)  printf("%I64d\n", x)
#define lowbit(x)   (x)&(-x)
#define Read()  freopen("a.txt", "r", stdin)
#define Write() freopen("b.txt", "w", stdout);
#define maxn 100010
#define mod 1000000007
using namespace std;
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
int sum[maxn<<2];
int add[maxn<<2];

void PushUp(int rt)
{
    sum[rt]=sum[rt<<1]+sum[rt<<1|1];
}

void PushDown(int rt,int m)
{
    if(add[rt])
    {
        add[rt<<1]+=add[rt];
        add[rt<<1|1]+=add[rt];
        sum[rt<<1]+=(m-(m>>1))*add[rt];
        sum[rt<<1|1]+=(m>>1)*add[rt];
        add[rt]=0;
    }
}

void build(int l,int r,int rt)
{
    add[rt]=0;
    if(l==r)
    {
        scanf("%d",&sum[rt]);
        return;
    }
    int m=(l+r)>>1;
    build(lson);
    build(rson);
    PushUp(rt);
}

void update(int L,int R,int c,int l,int r,int rt)
{
    if(L<=l&&r<=R)
    {
        add[rt]+=c;
        sum[rt]+=c*(r-l+1);
        return;
    }
    PushDown(rt,r-l+1);
    int m=(l+r)>>1;
    if(L<=m) update(L,R,c,lson);
    if(m<R) update(L,R,c,rson);
    PushUp(rt);
}

int query(int L,int R,int l,int r,int rt)
{
    if(L<=l&&r<=R)
    {
        return sum[rt];
    }
    PushDown(rt,r-l+1);
    int m=(l+r)>>1;
    int ret=0;
    if(L<=m) ret+=query(L,R,lson);
    if(m<R) ret+=query(L,R,rson);
    return ret;
}
int main()
{
   // freopen("a.txt","r",stdin);
    int n,m,q;
    while(~scanf("%d%d%d",&n,&m,&q))
    {
        build(1,n,1);
        int ans,x;
        while(q--)
        {
            scanf("%d",&x);
            ans=query(x,x+m-1,1,n,1);
            update(x,x+m-1,-1,1,n,1);
            printf("%d\n",ans);
        }
    }
    return 0;
}