hdu 1166 敌兵布阵

第一个线段树，参考别人代码

#include<iostream>
#include<cctype>
#include<cstdlib>
#include<cstring>
#include<cstdio>
using namespace std;

const int MAXN = 55555;
int sum[MAXN << 2];

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

void build(int l, int r, int rt)
{
    if(l == r)
    {
        scanf("%d",&sum[rt]);
        return;
    }
    int mid = (l + r) >> 1;
    build(l, mid, rt << 1);
    build(mid + 1, r, rt << 1 | 1);
    PushUp(rt);
}

void update(int p, int add, int l, int r, int rt)
{
    if(l == r)
    {
        sum[rt] += add;
        return;
    }
    int mid = (l + r) >> 1;
    if(p <= mid)
        update(p, add, l, mid, rt << 1);
    else
        update(p, add, mid + 1, r, rt << 1 | 1);
    PushUp(rt);
}

int query(int ll, int rr, int l, int r, int rt)
{
    if(ll <= l && rr >= r)
        return sum[rt];
    int mid = (l + r) >> 1;
    int ret = 0;
    if(ll <= mid)
        ret += query(ll, rr, l, mid, rt << 1);
    if(rr > mid)
        ret += query(ll, rr, mid +1, r, rt << 1 | 1);
    return ret;
}

int main()
{
    int t,c;
    char d[10];
    scanf("%d", &t);
    for(c = 1; c <= t; c++){
        printf("Case %d:\n", c);
        int n;
        scanf("%d", &n);
        build(1,n,1);
        while(scanf("%s",d) != EOF)
        {
            if(d[0] == 'E')
                break;
            int x,y;
            scanf("%d%d",&x,&y);
            if(d[0] == 'Q')
            {
                int ans = query(x, y, 1, n, 1);
                printf("%d\n",ans);
            }
            if(d[0] == 'S')
                update(x,-y,1,n,1);
            if(d[0] == 'A')
                update(x, y,1,n,1);
        }
    }
    return 0;
}

 

#include<iostream>
#include<cctype>
#include<cstdlib>
#include<cstring>
#include<cstdio>
using namespace std;

struct seg
{
    int l;
    int r;
    int n;
}T[150011];

void build(int l, int r, int k)
{
    int mid;
    if(l == r){
        T[k].l = l;
        T[k].r = r;
        T[k].n = 0;
        return ;
    }

    mid = (l + r)/2;
    T[k].l = l;
    T[k].r = r;
    T[k].n = 0;
    build(l,mid,2*k);
    build(mid+1,r,2*k+1);
}

void insert(int n,int d,int k)
{
    int mid;
    if(T[k].l == T[k].r && T[k].l == d)
    {
        T[k].n += n;
        return;
    }
    mid = (T[k].l + T[k].r)>>1;
    if(d <= mid) insert(n,d,2*k);
    else insert(n,d,2*k + 1);
    T[k].n = T[2*k].n + T[2*k + 1].n;
}

int ans;
void search(int l, int r, int k)
{
    int mid;
    if(T[k].l == l && T[k].r == r)
    {
        ans += T[k].n;
        return;
    }
    mid = (T[k].l + T[k].r) >> 1;
    if(r <= mid) search(l,r,2*k);
    else if(l > mid) search(l,r,2*k +1);
    else
    {
        search(l,mid,2*k);
        search(mid + 1,r,2*k+1);
    }
}

int main(){
    int Case,TT;
    int n;
    int i;
    int temp;
    char str[11];
    int a,b;
    scanf("%d",&TT);
    for(Case = 1;Case <= TT; Case++)
    {
        scanf("%d",&n);

        build(1,n,1);
        for(i = 1; i <= n; i++)
        {
            scanf("%d",&temp);
            insert(temp,i,1);
        }

        printf("Case %d:\n",Case);

        while(scanf("%s",str),strcmp(str,"End"))
        {
            scanf("%d%d",&a,&b);
            if(strcmp(str,"Add")==0)
                insert(b,a,1);
            else if(strcmp(str,"Sub")==0)
                insert(-b,a,1);
            else{
                ans = 0;
                search(a,b,1);
                printf("%d\n",ans);
            }
        }
    }

    return 0;
}