题意:
求一个长度为n的整数序列,使得给定的m个区间内没有相同的数字。
思路:
从前往后贪心填数字,用set维护一下当前区间可以填充的数字,每次填数字时填最小那个。注意序列中有些位置可能没有被任何区间覆盖。
代码:
#include <iostream>
#include <iomanip>
#include <algorithm>
#include <cstring>
#include <cctype>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <map>
#include <list>
#include <set>
#include <stack>
#include <queue>
#include <string>
#include <sstream>
#define pb push_back
#define X first
#define Y second
#define lch (o<<1)
#define rch (o<<1|1)
#define ALL(x) x.begin(),x.end()
#define INS(x) inserter(x,x.begin())
#define pii pair<int,int>
#define qclear(a) while(!a.empty())a.pop();
#define lowbit(x) (x&-x)
#define sd(n) scanf("%d",&n)
#define sdd(n,m) scanf("%d%d",&n,&m)
#define sddd(n,m,k) scanf("%d%d%d",&n,&m,&k)
#define mst(a,b) memset(a,b,sizeof(a))
#define cout3(x,y,z) cout<<x<<" "<<y<<" "<<z<<endl
#define cout2(x,y) cout<<x<<" "<<y<<endl
#define cout1(x) cout<<x<<endl
#define IOS std::ios::sync_with_stdio(false)
#define SRAND srand((unsigned int)(time(0)))
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int uint;
using namespace std;
const double PI=acos(-1.0);
const int INF=0x3f3f3f3f;
const ll mod=1e9+7;
const double eps=1e-8;
const int maxn=100005;
const int maxm=10005;
struct node {
int l,r;
bool operator < (const node& o)const {
if(l==o.l)
return r>o.r;
return l<o.l;
}
};
int n,m;
node p[maxn];
int ans[maxn];
void solve() {
int t;
sd(t);
while(t--) {
set<int>s;
sdd(n,m);
for(int i=0; i<m; i++) {
sdd(p[i].l,p[i].r);
}
sort(p,p+m);
for(int i=1; i<=n; i++) {
s.insert(i);
ans[i]=1;
}
int lastl=0,lastr=0;
int posl=p[0].l,posr=p[0].l;
for(int i=0;i<m;i++){
if(p[i].l>lastl&&p[i].r>lastr){
for(int j=posl;j<p[i].l;j++){
if(ans[j]==0)break;
s.insert(ans[j]);
}
posr=max(posr,p[i].l);
for(int j=posr;j<=p[i].r;j++){
ans[j]=*s.begin();
s.erase(s.begin());
}
lastl=p[i].l;
lastr=p[i].r;
posl=lastl;
posr=lastr+1;
}
}
for(int i=1; i<=n; i++) {
printf("%d%c",ans[i],(i==n)?'\n':' ');
}
}
return ;
}
int main() {
#ifdef LOCAL
freopen("in.txt","r",stdin);
// freopen("out.txt","w",stdout);
#else
// freopen("","r",stdin);
// freopen("","w",stdout);
#endif
solve();
return 0;
}