Hdu3397Sequence operation线段树

最新推荐文章于 2019-10-06 08:12:56 发布

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最新推荐文章于 2019-10-06 08:12:56 发布

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CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/yigexigua/p/3928293.html

本文深入探讨了线段树的使用与优化技巧，并通过实例展示了如何解决复杂问题。包括线段树的基本概念、实现细节及在实际问题中的应用。

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　　这题不得不吐槽下了，这是我没有搜题解1a的题，让我又有继续做线段树的动力。几个东西揉在一块。

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <climits>
#include <string>
#include <iostream>
#include <map>
#include <cstdlib>
#include <list>
#include <set>
#include <queue>
#include <stack>
#include<math.h>
#include<vector>
using namespace std;
const int maxn = 111111;
int color[maxn << 2], sign[maxn << 2];
int sum[maxn << 2], lsum[maxn << 2], rsum[maxn << 2];
int sum1[maxn << 2], lsum1[maxn << 2], rsum1[maxn << 2];
int ans[maxn << 2];
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1

void below(int rt, int m)
{
    if (~color[rt]) color[rt] ^= 1;
    else sign[rt] ^= 1;
    ans[rt] = m - ans[rt]; swap(sum[rt], sum1[rt]); swap(lsum[rt], lsum1[rt]); swap(rsum[rt], rsum1[rt]);// 对于处理 0,1互换的情况，我维护两个东西，一个记录连续1，一个记录连续0。执行互换时只需要将这两部分互换即可
}

void down(int rt, int m)
{
    if (~color[rt]){
        sign[rt << 1] = sign[rt << 1 | 1] = 0;
        color[rt << 1] = color[rt << 1 | 1] = color[rt];
        if (color[rt] == 1){
            ans[rt << 1] = m - (m >> 1); sum[rt << 1] = lsum[rt << 1] = rsum[rt << 1] = m - (m >> 1);
            sum1[rt << 1] = rsum1[rt << 1] = lsum1[rt << 1] = 0;
            ans[rt << 1 | 1] = (m >> 1); sum[rt << 1 | 1] = lsum[rt << 1 | 1] = rsum[rt << 1 | 1] = (m >> 1);
            sum1[rt << 1 | 1] = rsum1[rt << 1 | 1] = lsum1[rt << 1 | 1] = 0;
        }
        if (color[rt] == 0){
            ans[rt << 1] = ans[rt << 1 | 1] = 0;
            sum[rt << 1] = lsum[rt << 1] = rsum[rt << 1] = sum[rt << 1 | 1] = lsum[rt << 1 | 1] = rsum[rt << 1 | 1] = 0;
            sum1[rt << 1] = lsum1[rt << 1] = rsum1[rt << 1] = (m - (m >> 1));
            sum1[rt << 1 | 1] = lsum1[rt << 1 | 1] = rsum1[rt << 1 | 1] = (m >> 1);
        }
        color[rt] = -1;
    }
    if (sign[rt]){
        below(rt << 1, (m - (m >> 1)));
        below(rt << 1 | 1, (m >> 1));
        sign[rt] = 0;
    }
}

void up(int rt, int m)
{
    ans[rt] = ans[rt << 1] + ans[rt << 1 | 1];
    lsum[rt] = lsum[rt << 1];
    rsum[rt] = rsum[rt << 1 | 1];
    if (lsum[rt] == (m - (m >> 1))) lsum[rt] += lsum[rt << 1 | 1];
    if (rsum[rt] == (m >> 1)) rsum[rt] += rsum[rt << 1];
    sum[rt] = max(max(sum[rt << 1], sum[rt << 1 | 1]), rsum[rt << 1] + lsum[rt << 1 | 1]);
    lsum1[rt] = lsum1[rt << 1];
    rsum1[rt] = rsum1[rt << 1 | 1];
    if (lsum1[rt] == (m - (m >> 1))) lsum1[rt] += lsum1[rt << 1 | 1];
    if (rsum1[rt] == (m >> 1)) rsum1[rt] += rsum1[rt << 1];
    sum1[rt] = max(max(sum1[rt << 1], sum1[rt << 1 | 1]), rsum1[rt << 1] + lsum1[rt << 1 | 1]);
}

void build(int l, int r, int rt)
{
    color[rt] = -1; sign[rt] = 0;
    if (l == r){
        scanf("%d", &ans[rt]);
        if (ans[rt]) sum[rt] = lsum[rt] = rsum[rt] = 1, lsum1[rt] = rsum1[rt] = sum1[rt] = 0;
        else sum1[rt] = lsum1[rt] = rsum1[rt] = 1, sum[rt] = lsum[rt] = rsum[rt] = 0;
        return;
    }
    int mid = (l + r) >> 1;
    build(lson);
    build(rson);
    up(rt, r - l + 1);
}

void update(int L, int R, int add, int  l, int r, int rt)
{
    if (L <= l&&r <= R){
        if (add == 1){
            color[rt] = 1; sign[rt] = 0; ans[rt] = r - l + 1;
            sum[rt] = lsum[rt] = rsum[rt] = r - l + 1;
            sum1[rt] = lsum1[rt] = rsum1[rt] = 0;
        }
        if (add == 0){
            color[rt] = 0; sign[rt] = 0; ans[rt] = 0;
            sum[rt] = lsum[rt] = rsum[rt] = 0;
            sum1[rt] = lsum1[rt] = rsum1[rt] = r - l + 1;
        }
        if (add == -1) below(rt,r-l+1);
        return;
    }
    int mid = (l + r) >> 1;
    down(rt, r - l + 1);
    if (L <= mid) update(L, R, add, lson);
    if (R > mid) update(L, R, add, rson);
    up(rt, r - l + 1);
}

int ask(int L, int R, int l, int r, int rt)
{
    if (L <= l&&r <= R) return ans[rt];
    down(rt, r - l + 1);
    int mid = (l + r) >> 1;
    int ret = 0;
    if (L <= mid) ret += ask(L, R, lson);
    if (R > mid) ret += ask(L, R, rson);
    return ret;

}

int ask1(int L, int R, int l, int r, int rt)
{
    if (L <= l&&r <= R) return sum[rt];
    int mid = (l + r) >> 1;
    down(rt, r - l + 1);
    int ret = 0;
    ret = min(mid - L + 1, rsum[rt << 1]) + min(R - mid, lsum[rt << 1 | 1]);
    if (L <= mid) ret = max(ret, ask1(L,R,lson));
    if (R > mid) ret = max(ret, ask1(L,R,rson));
    return ret;
}

int main()
{
    int Icase; int n; int m; int a; int b; int c;
    scanf("%d", &Icase);
    while (Icase--){
        scanf("%d%d", &n, &m);
        build(1, n, 1);
        for (int i = 0; i < m; i++){
            //printf("jijidajiji%d\n", sum[1]);
            scanf("%d%d%d", &a, &b, &c);
            b++; c++;
            if (a == 0) update(b, c, 0, 1, n, 1);
            if (a == 1) update(b, c, 1, 1, n, 1);
            if (a == 2) update(b, c, -1, 1, n, 1);
            if (a == 3){
                int t = ask(b, c, 1, n, 1);
                printf("%d\n", t);
            }
            if (a == 4){
                int  t = ask1(b, c, 1, n, 1);
                //printf("chaojixiaojiji %d\n", ask1(3, 3, 1, n, 1));
                printf("%d\n", t);
            }
        }
    }
    return 0;
}