线段树 && 树状数组

啊哈！第一篇文章~

屠龙宝刀点击就送

树状数组 ↓

#include<iostream>
#include<cstdio>
using namespace std;
const int MAXN = 100010;
int n, num[MAXN], c[MAXN];

void add(int loc, int value)
{
    for(int i = loc; i <= n; i += i & (-i))
        c[i] += value;
}

int ask(int a, int b)
{
    int ans = 0;
    for(int i = b; i > 0; i -= i & (-i))
        ans += c[i];
    for(int i = a - 1; i > 0; i -= i & (-i))
        ans -= c[i];
    return ans;
}

int main()
{
    scanf("%d", &n);
    for(int i = 1; i <= n; i++)
    {
        scanf("%d", &num[i]);
        add(i, num[i]);
    }
    int m, op, a, b;
    scanf("%d", &m);
    for(int i = 1; i <= m; i++)
    {
        scanf("%d%d%d", &op, &a, &b);
        if(op == 1)
            add(a, b);
        if(op == 2)
            printf("%d\n", ask(a, b));
    }
    return 0;
}

线段树 ↓

#include<iostream>
#include<cstdio>
using namespace std;
const int MAXN = 200010;
typedef long long LL;
int n, num[MAXN];
struct dot
{
    int l, r;
    LL sum, add;
}tree[MAXN << 2];

void pushdown(int now)
{
    if(tree[now].add)
    {
        tree[now << 1].sum += tree[now].add * (tree[now << 1].r - tree[now << 1].l + 1);
        tree[now << 1].add += tree[now].add;
        tree[now << 1 | 1].sum += tree[now].add * (tree[now << 1 | 1].r - tree[now << 1 | 1].l + 1);
        tree[now << 1 | 1].add += tree[now].add;
        tree[now].add = 0;
    }
}

void update(int now)
{
    tree[now].sum = tree[now << 1].sum + tree[(now << 1) + 1].sum;
}

void build(int now, int l, int r)
{
    tree[now].l = l;
    tree[now].r = r;
    if(l == r)
    {
        tree[now].sum = num[l];
        return ;
    }
    int mid = (l + r) >> 1;
    build(now << 1, l, mid);
    build(now << 1 | 1, mid + 1, r);
    update(now);
}

void point_change(int now, int l, int r, int pos, LL value)
{
    if(l == r)
    {
        tree[now].sum += value;
        return ;
    }
    pushdown(now);
    int mid = (l + r) >> 1;
    if(pos <= mid)
        point_change(now << 1, l, mid, pos, value);
    else
        point_change((now << 1) + 1, mid + 1, r, pos, value);
    update(now);
}

void change(int now, int l ,int r, LL value)
{
    if(l <= tree[now].l && tree[now].r <= r)
    {
        tree[now].sum += (tree[now].r - tree[now].l + 1) * value;
        tree[now].add += value;
        return ;
    }
    int mid = (tree[now].l + tree[now].r) >> 1;
    pushdown(now);
    if(l <= mid)
    {
        change(now << 1, l, r, value);
    }
    if(r > mid) 
    {
        change(now << 1 | 1, l, r, value);
    }
    update(now);
}

LL ask(int now, int l, int r)
{
    if(tree[now].l >= l && r >= tree[now].r)
    {
        return tree[now].sum;
    }
    pushdown(now);
    int mid = (tree[now].l + tree[now].r) >> 1;
    LL ans = 0;
    if(l <= mid)
    {
        ans += ask(now << 1, l, r);
    }
    if(r > mid)
    {
        ans += ask(now << 1 | 1, l, r);
    }
    return ans;
}

int main()
{
    scanf("%d", &n);
    for(int i = 1; i <= n; i++)
    {
        scanf("%d", &num[i]);
    }
    build(1, 1, n);
    int m, op, a, b;
    scanf("%d", &m);
    for(int i = 1; i <= m; i++)
    {
        scanf("%d", &op);
        if(op == 1)
        {
            LL value;
            scanf("%d%d%lld", &a, &b, &value);
            change(1, a ,b, value);
            point_change(1, 1, n, a, b);
        }
        if(op == 2)
        {
            scanf("%d%d", &a, &b);
            printf("%lld\n", ask(1, a, b));
        }
    }
    return 0;
}