线段树区间修改 懒惰标记 维护和、最大值、最小值

6
1 5 10 1577
1 1 7 3649
0 8 10
0 1 4
1 6 8 157
1 3 4 1557

4731
14596

#include <cstdio>
#include <cstring>

#define maxn 100000 + 10
#define Lson L, mid, rt<<1
#define Rson mid+1, R, rt<<1|1

int min(int a, int b) {return a<b ? a : b;}
int max(int a, int b) {return a>b ? a : b;}

struct Node
{
    int sum, Min, Max, lazy;
} T[maxn<<2];

void PushUp(int rt)
{
    T[rt].sum = T[rt<<1].sum + T[rt<<1|1].sum;
    T[rt].Min = min(T[rt<<1].Min, T[rt<<1|1].Min);
    T[rt].Max = max(T[rt<<1].Max, T[rt<<1|1].Max);
}

void PushDown(int L, int R, int rt)
{
    int mid = (L + R) >> 1;
    int t = T[rt].lazy;
    T[rt<<1].sum = t * (mid - L + 1);
    T[rt<<1|1].sum = t * (R - mid);
    T[rt<<1].Min = T[rt<<1|1].Min = t;
    T[rt<<1].Max = T[rt<<1|1].Max = t;
    T[rt<<1].lazy = T[rt<<1|1].lazy = t;
    T[rt].lazy = 0;
}

void Build(int L, int R, int rt)
{
    if(L == R)
    {
        scanf("%d", &T[rt].sum);
        T[rt].Min = T[rt].Max = T[rt].sum;
        return ;
    }
    int mid = (L + R) >> 1;
    Build(Lson);
    Build(Rson);
    PushUp(rt);
}

void Update(int l, int r, int v, int L, int R, int rt)
{
    if(l==L && r==R)//修改区间值
    {
        T[rt].lazy = v;
        T[rt].sum = v * (R - L + 1);
        T[rt].Min = T[rt].Max = v;
        return ;
    }
    int mid = (L + R) >> 1;
    if(T[rt].lazy) PushDown(L, R, rt);//向下更新一级
    if(r <= mid) Update(l, r, v, Lson);
    else if(l > mid) Update(l, r, v, Rson);
    else
    {
        Update(l, mid, v, Lson);
        Update(mid+1, r, v, Rson);
    }
    PushUp(rt);
}

int Query(int l, int r, int L, int R, int rt)
{
    if(l==L && r== R)
        {
            printf("(%d, %d)---Min: %d   Max: %d  Sum: %d  \n", L, R, T[rt].Min, T[rt].Max, T[rt].sum);
            return T[rt].sum;
        }
    int mid = (L + R) >> 1;
    if(T[rt].lazy) PushDown(L, R, rt);
    if(r <= mid) return Query(l, r, Lson);
    else if(l > mid) return Query(l, r, Rson);
    return Query(l, mid, Lson) + Query(mid + 1, r, Rson);
}

int main()
{
    int n, q;
    scanf("%d", &n);
    Build(1, n, 1);
    scanf("%d", &q);
    int a, b, c, d;
    while(q--)
    {
        scanf("%d%d%d", &a, &b, &c);
        if(a)
        {
            scanf("%d", &d);
            Update(b, c, d, 1, n, 1);
        }
        else printf("%d\n", Query(b, c, 1, n, 1));
    }
    return 0;
}

/*

6
1 2 3 4 5 6
3
0 1 4
1 2 3 0
0 1 4

*/