poj3468

线段树和树状数组的区间查询和区间更改
POJ 3468

线段树的代码长度，占用内存，运行时间都比树状数组多。。。不知道为啥。

线段树
用了lazy标记，tag

#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;
#define sc(x) scanf("%d", &x);
#define scs(x) scanf("%s", x);
#define scc(x) scanf("%c", &x);
const int maxn = 100010;
typedef long long ll;
struct node{
    int l, r;
    ll tag, sum;
}tree[maxn<<2];
int in[maxn];
ll sum;
void pushUp(int idx){
    tree[idx].sum = tree[idx<<1].sum + tree[idx<<1|1].sum;
}
void build(int l, int r, int idx){
    tree[idx].l = l;
    tree[idx].r = r;
    if(l == r){
        tree[idx].sum = in[l];
        return;
    }
    int mid = (l+r)>>1;
    build(l, mid, idx<<1);
    build(mid+1, r, idx<<1|1);
    pushUp(idx);
}
void pushDown(int idx){
    int mid = (tree[idx].l+tree[idx].r)>>1;
    tree[idx<<1].sum += (mid - tree[idx].l+1)*tree[idx].tag;
    tree[idx<<1|1].sum += (tree[idx].r - mid)*tree[idx].tag;
    tree[idx<<1].tag += tree[idx].tag;
    tree[idx<<1|1].tag += tree[idx].tag;
    tree[idx].tag = 0;
}
void query(int l, int r, int idx){
    if(tree[idx].l >= l && tree[idx].r <= r){
        sum += tree[idx].sum;
        return ;
    }
    if(tree[idx].tag != 0)
        pushDown(idx);
    int mid = (tree[idx].l+tree[idx].r)>>1;
    if(r <= mid) query(l, r, idx<<1);
    else if(l > mid) query(l, r, idx<<1|1);
    else{
        query(l, r, idx<<1);
        query(l, r, idx<<1|1);
    }
}
void updata(int l, int r, int val, int idx){
    if(l <= tree[idx].l && r >= tree[idx].r){
        tree[idx].sum += (tree[idx].r-tree[idx].l+1)*val;
        tree[idx].tag += val;
        return ;
    }
    if(tree[idx].tag != 0)
        pushDown(idx);
    int mid = (tree[idx].l+tree[idx].r)>>1;
    if(r <= mid) updata(l, r, val, idx<<1);
    else if(l > mid) updata(l, r, val, idx<<1|1);
    else {
        updata(l, r, val, idx<<1);
        updata(l, r, val, idx<<1|1);
    }
    pushUp(idx);
}
int main(){
    int n, k;
    sc(n);sc(k);
    for(int i = 1; i <= n; i++){
        sc(in[i]);
    }
    build(1, n, 1);
    for(int i = 1; i <= k; i++){
        getchar();
        char s;
        scc(s);
        int l, r;
        sc(l);sc(r);
        if(s=='Q'){
            sum = 0;
            query(l, r, 1);
            printf("%lld\n", sum);
        }else{
            int val;
            sc(val);
            updata(l, r, val, 1);
        }
    }
    return 0;
} 

树状数组
用了差分

#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;
typedef long long ll;
const int MAXN = 100010;
int n;
ll sum1[MAXN],sum2[MAXN], a[MAXN]={0};
//区间更新，区间求和
ll lowbit(ll x){
    return x&(-x);
}
void updata(ll i,ll k){
    ll x = i;    //因为x不变，所以得先保存i值
    while(i <= n){
        sum1[i] += k;
        sum2[i] += k * (x-1);
        i += lowbit(i);
    }
}
ll getsum(ll i){        //求前缀和
    ll res = 0, x = i;
    while(i > 0){
        res += x * sum1[i] - sum2[i];
        i -= lowbit(i);
    }
    return res;
}
int main(){
    int k;
    scanf("%d%d", &n, &k);
    for(int i = 1; i <= n; i++){
        scanf("%lld", &a[i]);
        updata(i,a[i] - a[i-1]);
    }
    //[x,y]区间内加上k
    for(int i = 1; i <= k; i++){
        char s;int x, y;
        getchar();
        scanf("%c %d %d", &s, &x, &y);
        if(s=='Q'){
            ll sum = getsum(y) - getsum(x-1);
            printf("%lld\n", sum);
        }else{
            int val;
            scanf("%d", &val);
            updata(x, val);updata(y+1, -val);
        }
    }
    return 0;
}