hihoCoder 1078 线段树的区间修改_Deng's site \#

还是最基础的线段树噢  这次是区间修改

#include<cstdio>
#include<cstring>
#include<algorithm>
#define lc p<<1,s,mid
#define rc p<<1|1,mid+1,e
#define mid (s+e)/2

using namespace std;
const int N = 100005;
int sum[4 * N], setv[4 * N];
void pushup(int p)
{
    sum[p] = (sum[p << 1] + sum[p << 1 | 1]);
}

void pushdown(int p, int s, int e)
{
    if(setv[p] == 0) return;
    sum[p << 1] = (mid - s + 1) * setv[p];
    sum[p << 1 | 1] = (e - mid) * setv[p];
    setv[p << 1] = setv[p];
    setv[p << 1 | 1] = setv[p];
    setv[p] = 0;
}

void build(int p, int s, int e)
{
    setv[p] = 0;
    if(s == e) scanf("%d", &sum[p]);
    else
    {
        build(lc);
        build(rc);
        pushup(p);
    }
}

void update(int p, int s, int e, int l, int r, int v)
{
    if(s >= l && e <= r)
    {
        setv[p] = v;
        sum[p] = (e - s + 1) * v;
        return;
    }
    pushdown(p, s, e);
    if(r <= mid) update(lc, l, r, v);
    else if(l > mid) update(rc, l, r, v);
    else update(lc, l, mid, v), update(rc, mid + 1, r, v);
    pushup(p);
}

int query(int p, int s, int e, int l, int r)
{
    if(s >= l && e <= r) return sum[p];
    pushdown(p, s, e);
    if(r <= mid) return query(lc, l, r);
    if(l > mid) return query(rc, l, r);
    return query(lc, l, mid) + query(rc, mid + 1, r);
}

int main()
{
    int n, m, a, b, c, op;
    while(~scanf("%d", &n))
    {
        build(1, 1, n);
        scanf("%d", &m);
        while(m--)
        {
            scanf("%d", &op);
            if(op)
            {
                scanf("%d%d%d", &a, &b, &c);
                update(1, 1, n, a, b, c);
            }
            else
            {
                scanf("%d%d", &a, &b);
                printf("%d\n", query(1, 1, n, a, b));
            }
        }
    }
    return 0;
}
#include<cstdio>
#incl