POJ 3468 A Simple Problem with Integers（线段树 区间更新）

Description

You have N integers, A₁,A₂, ... , A_N. You need to deal with two kinds of operations. One type of operation is to add some given number to each number in a given interval. The other is to ask for the sum of numbers in a given interval.

Input

The first line contains two numbers N and Q. 1 ≤ N,Q ≤ 100000.
The second line contains N numbers, the initial values of A₁,A₂, ... , A_N. -1000000000 ≤A_i ≤ 1000000000.
Each of the next Q lines represents an operation.
"C a b c" means adding c to each of A_a,A_a+1, ... ,A_b. -10000 ≤ c ≤ 10000.
"Q a b" means querying the sum of A_a,A_a+1, ... ,A_b.

Output

You need to answer all Q commands in order. One answer in a line.

Sample Input

10 51 2 3 4 5 6 7 8 9 10Q 4 4Q 1 10Q 2 4C 3 6 3Q 2 4

Sample Output

455915

线段树区间更新。

#include <stdio.h>#include <string.h>#include <algorithm>#include <math.h>#define lson o << 1, l, m#define rson o << 1|1, m+1, rusing namespace std;typedef long long LL;const int MAX=0x3f3f3f3f;const int maxn = 111111;int n, q, a, b, c;LL sum[maxn<<2], add[maxn<<2];void up(int o) {    sum[o] = sum[o<<1] + sum[o<<1|1];}void down(int o, int m) {    if(add[o] != 0) {        add[o<<1] += add[o];        add[o<<1|1] += add[o];        sum[o<<1] += add[o]*(m-(m>>1));        sum[o<<1|1] += add[o]*(m>>1);        add[o] = 0;    }}void build(int o, int l, int r) {    add[o] = 0;    if(l == r) scanf("%I64d", &sum[o]);    else {        int m = (l+r) >> 1;        build(lson);        build(rson);        up(o);    }}LL query(int o, int l, int r) {    if(a <= l && r <= b) return sum[o];    down(o, r-l+1);    int m = (l+r) >> 1;    LL ans = 0;    if(a <= m) ans += query(lson);    if(m < b) ans += query(rson);    return ans;}void update(int o, int l, int r) {    if(a <= l && r <= b) {        add[o] += c;        sum[o] += (LL)c*(r-l+1);        return;    }    int m = (l+r) >> 1;    down(o, r-l+1);    if(a <= m) update(lson);    if(m < b) update(rson);    up(o);}int main(){    scanf("%d%d", &n, &q);    build(1, 1, n);    while(q--) {        char op[3];        scanf("%s",op);        if(op[0] == 'C') {            scanf("%d%d%d", &a, &b, &c);            update(1, 1, n);        } else {            scanf("%d%d", &a, &b);            printf("%I64d\n", query(1, 1, n));        }    }    return 0;}