PKU 3468 A Simple Problem with Integers

区间修改，询问，带有 lazy tag。

# include <stdio.h>



# define ls ((r) << 1)

# define rs ((r) << 1 | 1)

# define mid (((x)+(y))>>1)



# define MAXN 100005



typedef long long int LL;



int a[MAXN];

LL sum[MAXN * 4];

LL lazy[MAXN * 4];



void update(int r)

{

    sum[r] = sum[ls] + sum[rs];

}



void build(int x, int y, int r)

{

    sum[r] = 0;

    lazy[r] = 0;

    if (x == y)

    {

        sum[r] = a[x];

        return ;

    }

    build(x, mid, ls);

    build(mid+1, y, rs);

    update(r);

}



void pushdown(int x, int y, int r)

{

    if (lazy[r])

    {

        lazy[ls] += lazy[r], lazy[rs] += lazy[r];

        sum[ls] += lazy[r]*(mid-x+1);

        sum[rs] += lazy[r]*(y-mid);

        lazy[r] = 0;

    }

}



void add(int x, int y, int r, int s, int t, LL val)

{

    if (s<=x && y<=t)

    {

        lazy[r] += val;

        sum[r] += val*(y-x+1);

        return ;

    }

    pushdown(x, y, r);

    if (s<=mid) add(x, mid, ls, s, t, val);

    if (mid+1<=t) add(mid+1, y, rs, s, t, val);

    update(r);

}



void query(int x, int y, int r, int s, int t, LL *p)

{

    if (s<=x && y<=t)

    {

        *p += sum[r];

        return ;

    }

    pushdown(x, y, r);

    if (s<=mid) query(x, mid, ls, s, t, p);

    if (mid+1<=t) query(mid+1, y, rs, s, t, p);

}



int main()

{

    LL ans;

    char od[5];

    int i, n, m, s, t, val;

    

    while (~scanf("%d%d", &n, &m))

    {

        for (i = 1; i <= n; ++i) scanf("%d", &a[i]);

        build(1, n, 1);

        for (i = 1; i <= m; ++i)

        {

            scanf("%s%d%d", od, &s, &t);

            if (od[0] == 'C') scanf("%d", &val), add(1, n, 1, s, t, val);

            else ans = 0, query(1, n, 1, s, t, &ans), printf("%lld\n", ans);

        }

    }

    

    return 0;

}