Count the Colors Time Limit: 2 Seconds Memory Limit: 65536 KB Painting some colored segments on a line, some previously painted segments may be covered by some the subsequent ones. Your task is counting the segments of different colors you can see at last.
Each of the following n lines consists of exactly 3 nonnegative integers separated by single spaces: All the numbers are in the range [0, 8000], and they are all integers. Input may contain several data set, process to the end of file.
If some color can't be seen, you shouldn't print it. Print a blank line after every dataset.
1 1 0 2 |
这道题大体意思就是,本来是一段无色的区间,然后进行n步操作来进行染色,在最后的时候分别输出以各种颜色为基准的区间数量有多少。
这道题最重要的一点就是这是区间的染色!!不能和平常的点集的建树和改变一样操作。我仿照kuangbin大佬的模板写了一遍,顺便记录心得~~在代码中给出;
#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
const int maxn = 8010;
struct ***
{
int l, r, col;
}tr[maxn<<2];//所建之树
int color[maxn];//每种颜色的区间数量
int temp;//用来判断区间前后的颜色是否连续
void build(int rt, int l, int r)
{
tr[rt].l = l;
tr[rt].r = r;
tr[rt].col = -1;
if (l + 1 == r)//不能出现点的请况
{
return;
}
int mid = ((l + r) >> 1);
build(rt << 1, l, mid);
build(rt << 1 | 1, mid, r);//这里不同的是;两个都是mid,从而达到了题目中所需的把区间作为点的实现;
}
void insert(int rt, int l, int r, int c)
{
if (l == r)return;//点的情况
if (tr[rt].col == c)return;//如果本来颜色相同,就不用继续了
if (l <= tr[rt].l&&r >= tr[rt].r)//如果这段区间被包含,直接区间的改颜色就好
{
tr[rt].col = c;
return;
}
if (tr[rt].col >= 0)//如果已经被染色过
{
tr[rt << 1 | 1].col = tr[rt << 1].col = tr[rt].col;//之前的颜色传下去
tr[rt].col = -2;//标记这是存在混合颜色的情况
}
int mid = ((tr[rt].l + tr[rt].r) >> 1);
if (r <= mid)//开始分情况进行染色
{
insert(rt << 1, l, r, c);
}
else if (l >= mid)
{
insert(rt << 1 | 1, l, r, c);
}
else
{
insert(rt << 1, l, mid, c);
insert(rt << 1 | 1, mid, r, c);
}
tr[rt].col = -2;
}
void count(int s)//开始数数量
{
if (tr[s].col == -1)
{
temp = -1;
return;
}
if (tr[s].col != -2)//只有一个颜色
{
if (tr[s].col != temp)//是否与之区间区间颜色相同
{
color[tr[s].col]++;
temp = tr[s].col;
}
return;
}
if (tr[s].l + 1 != tr[s].r)//存在2个以上的单位区间才进行下部操作,防止访问点;
{
count(s << 1);
count(s << 1 | 1);
}
}
int main()
{
int n, a, b, c;
int Max;
while (scanf("%d", &n) != EOF)
{
build(1, 0, 8000);//建树
Max = 0;//记录最大的颜色标号
while (n--)
{
scanf("%d%d%d", &a, &b, &c);
insert(1, a, b, c);
if (c > Max)
{
Max = c;
}
}
// cout << Max << endl;
temp = -1;
memset(color, 0, sizeof(color));
count(1);//开始计数
for (int s = 0; s <= Max; s++)
{
if (color[s])printf("%d %d\n", s, color[s]);//输出;
}
printf("\n");
}
}