线段树

hdu1166敌兵布阵http://acm.hdu.edu.cn/showproblem.php?pid=1166

建树、单点修改、查询

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#define lson l, m, rt<<1
#define rson m+1, r, rt<<1|1
#define IO ios::sync_with_stdio(false);cin.tie(0);
#define INF 1e9
typedef long long ll;
using namespace std;
int t, n, sum[50010<<2], a, b, ans;
char s[20];
void PushUP(int rt)
{
    sum[rt] = sum[rt<<1]+sum[rt<<1|1];
}
void build(int l, int r, int rt)
{
    if(l == r){
        cin >> sum[rt];
        return ;
    }
    int m = (l+r)>>1;
    build(lson);
    build(rson);
    PushUP(rt);
}
void update(int p, int add, int l, int r, int rt)
{
    if(l == r){
        sum[rt] += add;
        return ;
    }
    int m = (l+r)>>1;
    if(p <= m){
        update(p, add, lson);
    }
    else{
        update(p, add, rson);
    }
    PushUP(rt);
}
int query(int L, int R, int l, int r, int rt)
{
    if(L <= l&&R >= r){
        return sum[rt];
    }
    int m = (l+r)>>1;
    int res = 0;
    if(L <= m){
        res += query(L, R, lson);
    }
    if(R > m){
        res += query(L, R, rson);
    } 
    return res;
}
int main()
{
    IO;
    int kase=0;
    cin >> t; 
    while(t--){
        cout << "Case " << ++kase << ":" << endl;
        cin >> n;
        build(1, n, 1); 
        while(cin >> s){
            if(s[0] == 'E'){
                break;
            }
            cin >> a >> b;
            if(s[0] == 'A'){
                update(a, b, 1, n, 1);
            }
            else if(s[0] == 'S'){
                update(a, -b, 1, n, 1);
            }
            else if(s[0] == 'Q'){
                cout << query(a, b, 1, n, 1) << endl;
            }
        }
    }
    return 0;
} 

hdu1698 Just a hookhttp://acm.hdu.edu.cn/showproblem.php?pid=1698

区间更新，更新值存在lazy数组里

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#define lson l, m, rt<<1
#define rson m+1, r, rt<<1|1
#define IO ios::sync_with_stdio(false);cin.tie(0);
#define INF 1e9
typedef long long ll;
using namespace std;
int t, n, m;
int sum[100010<<2], lazy[100010<<2];
void PushUP(int rt)
{
    sum[rt] = sum[rt<<1]+sum[rt<<1|1]; 
}
void build(int l, int r, int rt)
{
    lazy[rt] = 0;//一定要写在if外面作初始化 
    if(l == r){
        sum[rt] = 1;
        return ;
    }
    int m = (l+r)>>1;
    build(lson);
    build(rson);
    PushUP(rt);
}
void PushDown(int rt, int m)
{
    if(lazy[rt]){
        lazy[rt<<1] = lazy[rt<<1|1] = lazy[rt];
        sum[rt<<1] = (m - (m>>1))*lazy[rt];
        sum[rt<<1|1] = (m>>1)*lazy[rt];
        lazy[rt] = 0;
    }
}
void update(int L, int R, int v, int l, int r, int rt)
{
    if(L <= l && R >= r){
        lazy[rt] = v;
        sum[rt] = v*(r-l+1);
        return ;
    }
    PushDown(rt, r-l+1);
    int m = (l+r)>>1;
    if(L <= m){
        update(L, R, v, lson);
    }
    if(R > m){
        update(L, R, v, rson);
    }
    PushUP(rt);
}
int main()
{
    IO;
    int x, y, z, kase=0;
    while(cin >> t){
        kase=0;
        while(t--){
            cin >> n;
            build(1, n, 1);
            cin >> m; 
            for(int i = 0; i < m; i++){
                cin >> x >> y >> z;
                update(x, y, z, 1, n, 1);
            }
            cout << "Case " << ++kase << ": The total value of the hook is ";
            cout << sum[1] << "." << endl;
        }
    }
    return 0;
}

https://vjudge.net/problem/POJ-3468

线段树区间更新（lazy数组）模板题

#include<iostream>
#include<cstdio>
#include<queue>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<map>
#define lson l, m, rt<<1
#define rson m+1, r, rt<<1|1
#define INF 0x3f3f3f3f
typedef long long ll;
using namespace std;
ll sum[100010<<2], lazy[100010<<2];
void PushUP(int rt)
{
    sum[rt] = sum[rt<<1]+sum[rt<<1|1];
}
void PushDown(int rt, int m)
{
    if(lazy[rt]){//若有标记下移 
        lazy[rt<<1] += lazy[rt];
        lazy[rt<<1|1] += lazy[rt]; 
        sum[rt<<1] += (m-(m>>1))*lazy[rt];
        sum[rt<<1|1] += (m>>1)*lazy[rt];
        lazy[rt] = 0;//取消本层标记 
    }
} 
void build(int l, int r, int rt)
{
    lazy[rt] = 0;//一定写在if外初始化 
    if(l == r){
        scanf("%lld", &sum[rt]);
        return ;
    }
    int m = (l+r)>>1;
    build(lson);
    build(rson);
    PushUP(rt);
} 
ll Query(int L, int R, int l, int r, int rt)
{
    if(L<=l&&R>=r){
        return sum[rt];
    }
    PushDown(rt, r-l+1);//向下更新 
    int m = (l+r)>>1;
    ll ans=0;
    if(L <= m) ans += Query(L, R, lson);
    if(R > m) ans += Query(L, R, rson);
    return ans;
}
void Update(int L, int R, ll add, int l, int r, int rt)
{
    if(L<=l&&R>=r){
        sum[rt] += (r-l+1)*add;
        lazy[rt] += add;
        return ;
    }
    PushDown(rt, r-l+1);//向下而更新 
    int m=(l+r)>>1;
    if(L <= m) Update(L, R, add, lson);
    if(R > m) Update(L, R, add, rson);
    PushUP(rt);
}
int main()
{
    int n, m, a, b;
    ll c;
    char op[3];
    scanf("%d%d", &n, &m);
    build(1, n, 1);
    for(int i = 0; i < m; i++){
        scanf("%s", &op);
        if(op[0] == 'Q'){
            scanf("%d%d", &a, &b);
            printf("%lld
", Query(a, b, 1, n, 1));
        }
        else{
            scanf("%d%d%lld", &a, &b, &c);
            Update(a, b, c, 1, n, 1);
        }
    } 
    return 0;
}