POJ2528

題目鏈接：http://poj.org/problem?id=2528

區間增減模板題，不論是update還是query中都要進行下放標記。

#include <iostream>
#include <cstdio>
#define lson l, m, x<<1
#define rson m+1, r, x<<1|1
using namespace std;

typedef long long type;

const int INF = (1<<31)-1;
const int maxn =100000 + 10;

type sum[maxn << 2];
type delta[maxn << 2];
type a[maxn];
type n, m;

void pushUp(int x)
{
    sum[x] = sum[x<<1] + sum[x<<1|1];
}

void pushDown(int x, int len)
{
    if (delta[x])
    {
        delta[x<<1] += delta[x];
		delta[x<<1|1] += delta[x];
        sum[x<<1] += (len - (len >> 1)) * delta[x];
        sum[x<<1|1] += (len >> 1) * delta[x];
        delta[x] = 0;
    }
}

void build(int l, int r, int x)
{
    if(l == r)
    {
        sum[x] = a[l];
        return;
    }
    int m=(l+r)>>1;
    build(lson);
    build(rson);
    pushUp(x);
}

void update(int l, int r, int x, int L, int R, type C)
{
    if (L <= l && r <= R)
    {
        sum[x] += C * (r-l+1);
        delta[x] += C;
        return ;
    }
    pushDown(x, r-l+1);
    int m = (l + r) >> 1;
    if (L <= m) update(lson, L, R, C);
    if (R >  m) update(rson, L, R, C);
    pushUp(x);
}

type query(int l, int r, int x, int L, int R)
{
    if (L <= l && r <= R)
    {
        return sum[x];
    }
    pushDown(x, r-l+1);
    int m = (l + r) >> 1;
    type ret = 0;
    if (L <= m) ret += query(lson, L, R);
    if (R >  m) ret += query(rson, L, R);
    return ret;
}

int main()
{
    scanf("%d%d",&n, &m);
    for (int i=0; i<n; i++) scanf("%I64dd",&a[i+1]);
    getchar();
    build(1, n, 1);
    for (int i=0; i<m; i++)
    {
        char c;
        scanf("%c",&c);
        getchar();
        if (c == 'C')
        {
            type a, b, c;
            scanf("%d%d%I64dd", &a, &b, &c);
            getchar();
            update(1, n, 1, a, b, c);
        }
        else
        {
            type a, b;
            scanf("%d%d", &a, &b);
            getchar();
            printf("%I64d\n", query(1, n, 1, a, b));
        }
    }

    return 0;
}