POJ 3468 A Simple Problem with Integers 【线段树】

#include <cstdio>
#include <cstring>
#include <ctype.h>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <deque>
#include <vector>
#include <queue>
#include <string>
#include <map>
#include <stack>
#include <set>
#include <numeric>
#include <sstream>

using namespace std;
typedef long long LL;

const double PI = 3.14159265358979323846264338327;
const double E = 2.718281828459;
const double eps = 1e-6;

const int MAXN = 0x3f3f3f3f;
const int MINN = 0xc0c0c0c0;
const int maxn = 1e5 + 5;
const int MOD = 1e9 + 7;

int n, q;
LL anssum;

struct Node
{
LL l, r;
LL addv, sum;
}tree[maxn << 2];

void maintain(int id)
{
if (tree[id].l >= tree[id].r)
return;
tree[id].sum = tree[id << 1].sum + tree[id << 1 | 1].sum;
}

void pushdown(int id)
{
if (tree[id].l >= tree[id].r)
return;
if (tree[id].addv)
{
int tmp = tree[id].addv;
tree[id << 1].addv += tmp;
tree[id << 1 | 1].addv += tmp;
tree[id << 1].sum += (tree[id << 1].r - tree[id << 1].l + 1) * tmp;
tree[id << 1 | 1].sum += (tree[id << 1 | 1].r - tree[id << 1 | 1].l + 1) * tmp;
tree[id].addv = 0;
}
}

void build(int id, LL l, LL r)
{
tree[id].l = l;
tree[id].r = r;
tree[id].addv = 0;
tree[id].sum = 0;
if (l == r)
{
tree[id].sum = 0;
return;
}
LL mid = (l + r) >> 1;
build(id << 1, l, mid);
build(id << 1 | 1, mid + 1, r);
maintain(id);
}

void updateAdd(int id, LL l, LL r, LL val)
{
if (tree[id].l >= l && tree[id].r <= r)
{
tree[id].addv += val;
tree[id].sum += (tree[id].r - tree[id].l + 1) * val;
return;
}
pushdown(id);
LL mid = (tree[id].l + tree[id].r) >> 1;
if (l <= mid)
updateAdd(id << 1, l, r, val);
if (mid < r)
updateAdd(id << 1 | 1, l, r, val);
maintain(id);
}

void query(int id, LL l, LL r)
{
if (tree[id].l >= l && tree[id].r <= r)
{
anssum += tree[id].sum;
return;
}
pushdown(id);
LL mid = (tree[id].l + tree[id].r) >> 1;
if (l <= mid)
query(id << 1, l, r);
if (mid < r)
query(id << 1 | 1, l, r);
maintain(id);
}

int main()
{
scanf("%d %d", &n, &q);
build(1, 1, n);
for (LL i = 1; i <= n; i++)
{
LL num;
cin >> num;
updateAdd(1, i, i, num);
}
char id;
LL x, y;
LL val;
while (q--)
{
scanf(" %c", &id);
if (id == 'C')
{
scanf("%lld %lld %lld", &x, &y, &val);
updateAdd(1, x, y, val);
}
else if (id == 'Q')
{
scanf("%lld %lld", &x, &y);
anssum = 0;
query(1, x, y);
cout << anssum << endl;
}
}
}