Division and Union

https://codeforces.com/contest/1101/problem/C

C++版本一

题解：

/*
*@Author:   STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG
#define RI register int
using namespace std;
typedef long long ll;
//typedef __int128 lll;
const int N=100000+10;
const int MOD=1e9+7;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const int INF = 0x3f3f3f3f;
int t,n,m,k,q;

struct Node
{
    int l;
    int r;
    int id;
    int f;
}ed[N];
bool cmp(const Node &x,const Node &y)
{
    if (x.l!=y.l) return x.l<y.l;
    return x.r<y.r;
}
bool cmp2(const Node &x,const Node &y)
{
    return x.id<y.id;
}
int main()
{
    scanf("%d",&t);
    while (t--)
    {
        int flag=0;
        scanf("%d",&n);
        for (int i=1;i<=n;++i)
        {
            scanf("%d%d",&ed[i].l,&ed[i].r);
            ed[i].id=i;
        }
        sort(ed+1,ed+n+1,cmp);
        int a;
        a=ed[1].r;
        ed[1].f=1;
        for (int i=2;i<=n;++i)
        {
            if (!flag)
            {
                if (ed[i].l<=a) a=max(a,ed[i].r),ed[i].f=1;
                else
                {
                    flag=1;
                    ed[i].f=2;
                }
            }
            else ed[i].f=2;

        }
        if (!flag) printf("-1\n");
        else
        {
            sort(ed+1,ed+n+1,cmp2);
            for (int i=1;i<=n;++i)
            {
                printf("%d ",ed[i].f);
            }
            printf("\n");
        }
    }
}

C++版本二

题解：根据题意两组区间不能有交集。所以至少有两块独立的合并后区间。

/*
*@Author:   STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG
#define RI register int
using namespace std;
typedef long long ll;
//typedef __int128 lll;
const int N=100000+10;
const int MOD=1e9+7;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const int INF = 0x3f3f3f3f;
int t,n,m,k,q;
int ans,cnt,flag,temp;

struct node{
    int l,r,id,f;
    bool operator <(const node &S)const{
        if(l==S.l)
            return r<S.r;
        return l<S.l;
    }
}e[N];
int c[N<<1];
char str;
int main()
{
#ifdef DEBUG
	freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
#endif
    //
    scanf("%d",&t);
    while(t--){
        scanf("%d",&n);
        for(int i=1;i<=n;i++){
            scanf("%d%d",&e[i].l,&e[i].r);
            e[i].id=i;
        }
        sort(e+1,e+n+1);
        int pos=e[1].r;
        flag=1;
        c[e[1].id]=1;
        q=1;
        for(int i=2;i<=n;i++){
            if(pos<e[i].l){
                flag=0;
                if(q==1)
                    q=2;
                else
                    q=1;
            }
            c[e[i].id]=q;
            pos=max(pos,e[i].r);
        }
        if(flag){
            printf("-1\n");
            continue;
        }
        for(int i=1;i<n;i++){
            printf("%d ",c[i]);
        }
        printf("%d\n",c[n]);
    }
    //cout << "Hello world!" << endl;
    return 0;
}