hdu4027 Can you answer these queries? (区间修改，区间查询)

对一个区间两种操作：

c x  y

1、使区间[x,y]的数等于其开方数（四舍五入）。

2、查询区间[x,y]的和。

剪枝：

当一个数小于等于1时其开方数将不再变化

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1、线段树

#include <cmath>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 100100;
typedef long long LL;
struct node {
    int l, r;
    LL sum;
    bool flag;
} tree[maxn*4];
LL num[maxn];

void PushUp(int rt)
{
    tree[rt].sum = tree[rt<<1].sum + tree[rt<<1|1].sum;
    tree[rt].flag = (tree[rt<<1].flag && tree[rt<<1|1].flag);
}
void build(int rt, int l, int r)
{
    tree[rt].l = l, tree[rt].r = r;
    if(l == r) {
        tree[rt].sum = num[l];
        if(tree[rt].sum <=1) tree[rt].flag = true;
        else tree[rt].flag = false;
        return ;
    }
    int m = (l + r) >>1;
    build(rt<<1, l, m);
    build(rt<<1|1, m+1, r);
    PushUp(rt);
}
void update(int rt, int l, int r)
{
    if(tree[rt].l == l && tree[rt].r == r)
    {
        if(tree[rt].flag) return  ;
        if(tree[rt].l == tree[rt].r)
        {
            tree[rt].sum = (LL)sqrt(tree[rt].sum);
            if(tree[rt].sum <= 1)
                tree[rt].flag  = true;
            return ;
        }
    }
    int m  = (tree[rt].l + tree[rt].r ) >>1;
    if( r <= m) update(rt<<1, l, r);
    else if(l > m) update(rt<<1|1, l, r);
    else
    {
        update(rt<<1, l, m);
        update(rt<<1|1, m+1, r);
    }
    PushUp(rt);
}
LL query(int rt, int l, int r)
{
    if(l == tree[rt].l && tree[rt].r == r) {
        return tree[rt].sum;
    }
    int m = (tree[rt].l + tree[rt].r) >>1;
    if(r <= m)  return query(rt<<1, l, r);
    else if( l > m) return query(rt<<1|1, l, r);
    else return query(rt<<1, l, m) + query(rt<<1|1, m+1, r);
}
int main()
{
    int i, n, m;
    int tp, a, b;
    int cas = 1;
    //freopen("d:\\in.txt","r",stdin);
    while(scanf("%d",&n)!=EOF) {
        for(i=1; i<=n; ++i) scanf("%I64d",&num[i]);
        build(1,1,n);
        scanf("%d",&m);
        printf("Case #%d:\n",cas++);
        while(m--) {
            scanf("%d%d%d",&tp,&a,&b);
            if(a>b) swap(a,b);
            if(tp==0) {
                update(1,a,b);
            } else {
                printf("%I64d\n",query(1,a,b) );
            }
        }
        printf("\n");
    }
    return 0;
}

2、树状数组

#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;

const int maxn = 100100;
typedef long long LL;
LL c[maxn], a[maxn];
int n;
int lowbit(int x) {return x&(-x);}
void update(int i, LL val) {for(; i<=n; i += lowbit(i)) c[i] += val;}
LL getsum(int i) {LL ret = 0; for(; i>0; i -= lowbit(i)) ret += c[i]; return ret; }

int main()
{
    int i, j, m;
    LL x;
    int v, l, r;
    int cas = 1;
    while(~scanf("%d",&n))
    {
        memset(c, 0, sizeof c );
        for(i=1; i<=n; ++i)
        {
            scanf("%I64d", &a[i]);
            update(i, a[i]);
        }
        scanf("%d",&m);
        printf("Case #%d:\n",cas++);
        while(m--)
        {
            scanf("%d%d%d",&v,&l,&r);
            if(l>r) swap(l, r);
            if(v==0)
            {
                if(getsum(r) - getsum(l-1) <= r - l + 1)
                    continue;
                else
                {
                    for(j=l; j<=r; ++j)
                    {
                        if(a[j] <= 1) continue;
                        update(j, -a[j]);
                        a[j] = (LL)sqrt(a[j]);
                        update(j,a[j]);
                    }
                }
            }else
            {
                LL ans = getsum(r) - getsum(l-1);
                printf("%I64d\n",ans);
            }
        }
        printf("\n");
    }
    return 0;
}