zoj 2334 分类： zoj templa...

可并堆，左偏树，这是神犇“顺手学的东西”

以下是左偏树的合并操作代码。

int merge(int x,int y)
{
//p[i] 结点i的权值，这里是维护大根堆
//d[i] 在i的子树中，i到叶子结点的最远距离.

if(!x) return y;
if(!y) return x;

if(p[x] < p[y]) std::swap(x, y);

r[x] = merge(r[x], y);
if(r[x]) fa[r[x]] = x;

if(d[l[x]] < d[r[x]]) std::swap(l[x], r[x]);//调整树的结构，使其满足左偏性质

d[x] = d[r[x]] + 1;
return x;
}

这个题还是比较直白的。。。

时间复杂度：O(m∗log2n)

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <string>
#include <map>
#include <vector>
#include <stack>
#include <queue>
#include <utility>
#include <iostream>
#include <algorithm>

template<class Num>void read(Num &x)
{
char c; int flag = 1;
while((c = getchar()) < '0' || c > '9')
if(c == '-') flag *= -1;
x = c - '0';
while((c = getchar()) >= '0' && c <= '9')
x = (x<<3) + (x<<1) + (c-'0');
x *= flag;
return;
}
template<class Num>void write(Num x)
{
if(x < 0) putchar('-'), x = -x;
static char s[20];int sl = 0;
while(x) s[sl++] = x%10 + '0',x /= 10;
if(!sl) {putchar('0');return;}
while(sl) putchar(s[--sl]);
}

const int maxn = 1e5 + 50 , maxm = maxn, Nya = -1;

int n, m, p[maxn];
int l[maxn], r[maxn], fa[maxn], d[maxn];

void init()
{
memset(l, 0, sizeof(l));
memset(r, 0, sizeof(r));
memset(fa, 0, sizeof(fa));
memset(d, 0, sizeof(d));

for(int i = 1; i <= n; i++) read(p[i]);

read(m);
}

int merge(int x,int y)
{
if(!x) return y;
if(!y) return x;

if(p[x] < p[y]) std::swap(x, y);

r[x] = merge(r[x], y);
if(r[x]) fa[r[x]] = x;

if(d[l[x]] < d[r[x]]) std::swap(l[x], r[x]);

d[x] = d[r[x]] + 1;
return x;
}
int root(int x)
{
while(fa[x]) x = fa[x]; return x;
}
int dec(int t)
{
int L = l[t], R = r[t];

fa[L] = fa[R] = 0;
l[t] = r[t] = d[t] = 0;

p[t] >>= 1;

return merge(merge(L, R), t);
}

void solve()
{
int u, v, ans;

d[0] = Nya;

while(m--)
{
read(u), read(v);

u = root(u), v = root(v);
ans = (u == v) ? Nya : p[merge(dec(u), dec(v))];

write(ans), puts("");
}
}

int main()
{
#ifndef ONLINE_JUDGE
freopen("2334.in","r",stdin);
freopen("2334.out","w",stdout);
#endif

while(scanf("%d", &n) != EOF)
init(), solve();

#ifndef ONLINE_JUDGE
fclose(stdin);
fclose(stdout);
#endif
return 0;
}

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转载于:https://www.cnblogs.com/dashgua/p/4722943.html