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hdu 4288 Coder（树形结构-线段树）

2024-07-21 00:25:19   222人阅读

<span style="font-family: 'Times New Roman'; font-size: 12px;">Coder</span>

Time Limit: 20000/10000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 3187    Accepted Submission(s): 1258


Problem Description
　　In mathematics and computer science, an algorithm describes a set of procedures or instructions that define a procedure. The term has become increasing popular since the advent of cheap and reliable computers. Many companies now employ a single coder to write an algorithm that will replace many other employees. An added benefit to the employer is that the coder will also become redundant once their work is done. 1
　　You are now the signle coder, and have been assigned a new task writing code, since your boss would like to replace many other employees (and you when you become redundant once your task is complete).
Your code should be able to complete a task to replace these employees who do nothing all day but eating: make the digest sum.
　　By saying “digest sum” we study some properties of data. For the sake of simplicity, our data is a set of integers. Your code should give response to following operations:
　　1. add x – add the element x to the set;
　　2. del x – remove the element x from the set;
　　3. sum – find the digest sum of the set. The digest sum should be understood by

　　where the set S is written as {a1, a2, ... , ak} satisfying a1 < a2 < a3 < ... < ak 
　　Can you complete this task (and be then fired)?
------------------------------------------------------------------------------
1 See http://uncyclopedia.wikia.com/wiki/Algorithm
 

Input
　　There’re several test cases.
　　In each test case, the first line contains one integer N ( 1 <= N <= 105 ), the number of operations to process.
　　Then following is n lines, each one containing one of three operations: “add x” or “del x” or “sum”.
　　You may assume that 1 <= x <= 109.
　　Please see the sample for detailed format.
　　For any “add x” it is guaranteed that x is not currently in the set just before this operation.
　　For any “del x” it is guaranteed that x must currently be in the set just before this operation.
　　Please process until EOF (End Of File).
 

Output
　　For each operation “sum” please print one line containing exactly one integer denoting the digest sum of the current set. Print 0 if the set is empty.
 

Sample Input
9
add 1
add 2
add 3
add 4
add 5
sum
add 6
del 3
sum
6
add 1
add 3
add 5
add 7
add 9
sum
 

Sample Output
3
4
5

Hint
C++ maybe run faster than G++ in this problem.
 


这题线段树有点分治的感觉，下面举个例子就明白了，看图：






#include <iostream>
#include <cstdio>
#include <map>
#include <vector>
using namespace std;

#define ll long long
const int maxn = 100010;
struct tree{
    int l , r , sum;
    ll mod[5];
}a[4*maxn];
struct OP{
    char op;
    int x;
    OP(char o = 'a' , int a = 0){
        op = o , x = a;
    }
};
int N , cnt , value[maxn];
map<int , int> mp;
vector<OP> operate;

void pushup(int k){
    a[k].sum = a[2*k].sum+a[2*k+1].sum;
    int x = a[2*k].sum%5;
    for(int i = 0; i < 5; i++){
        a[k].mod[(x+i)%5] = a[2*k].mod[(x+i)%5]+a[2*k+1].mod[i];
    }
}

void build(int l , int r , int k){
    a[k].l = l;
    a[k].r = r;
    a[k].sum = 0;
    for(int i = 0; i < 5; i++) a[k].mod[i] = 0;
    if(l != r){
        int mid = (l+r)/2;
        build(l ,mid , 2*k);
        build(mid+1 , r , 2*k+1);
    }
}

void update(int l , int r , int k , int c){
    if(l <= a[k].l && a[k].r <= r){
        if(c < 0) a[k].sum -= 1;
        else a[k].sum += 1;
        a[k].mod[1] += c;
    }else{
        int mid = (a[k].l+a[k].r)/2;
        if(mid >= r) update(l , r , 2*k , c);
        else update(l , r , 2*k+1 , c);
        pushup(k);
    }
}

void initial(){
    mp.clear();
    cnt = 0;
    operate.clear();
}

void readcase(){
    char op[10];
    int x;
    for(int i = 0; i < N; i++){
        scanf("%s" , op);
        if(op[0] == 'a' || op[0] == 'd'){
            scanf("%d" , &x);
            operate.push_back(OP(op[0] , x));
            mp[x] = 0;
        }else operate.push_back(OP(op[0] , -1));
    }
    for(map<int , int>::iterator it = mp.begin(); it != mp.end(); it++){
        it->second = cnt;
        value[cnt++] = it->first;
    }
}

void computing(){
    build(0 , cnt-1 , 1);
    for(int i = 0; i < N; i++){
        char op = operate[i].op;
        int x = operate[i].x;
        if(op == 'a') update(mp[x] , mp[x] , 1 , x);
        else if(op == 'd') update(mp[x] , mp[x] , 1 , -1*x);
        else{
            printf("%I64d\n" , a[1].mod[3]);
        }
    }
}

int main(){
    while(~scanf("%d" , &N)){
        initial();
        readcase();
        computing();
    }
    return 0;
}


 

hdu 4288 Coder（树形结构-线段树）


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