typical90_029.cpp

#include <bits/stdc++.h>
#include <atcoder/lazysegtree>
#include <atcoder/segtree>
#define overload4(_1, _2, _3, _4, name, ...) name
#define rep1(n) for(ll i = 0; i < (n); ++i)
#define rep2(i, n) for(ll i = 0; i < (n); ++i)
#define rep3(i, a, b) for(ll i = (a); i < (b); ++i)
#define rep4(i, a, b, c) for(ll i = (a); i < (b); i += (c))
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)

#define forn(i, n) for(int i = 0 ; (i) < (n) ; ++i)
#define rrep(i,a,n) for (int i=n-1;i>=a;i--)
#define ALL(x) x.begin(),x.end()

#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define pause "read -p 'Press Enter to continue...' var"

using namespace std;
using namespace atcoder;

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }

/*
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*/

typedef long long ll;
typedef vector<ll> vll;
typedef pair<ll,ll> pll;

//const ll INF = numeric_limits<ll>::max()/4;
const ll MAX = 200005;
const int MOD = 3;
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};

using S = long long;
using F = long long;

const S INF = 8e18;
const F ID = 8e18;

S op(S a, S b){ return std::max(a, b); }
S e(){ return -INF; }
S mapping(F f, S x){ return (f == ID ? x : f); }
F composition(F f, F g){ return (f == ID ? g : f); }
F id(){ return ID; }

int main(){
  ll w, n;
  cin >> w >> n;
  vector<S> v;
  rep(i,w) v.pb(0);
  lazy_segtree<S, op, e, F, mapping, composition, id> seg(v);
  rep(n){
    ll l, r;
    cin >> l >> r;
    ll height = seg.prod(l - 1, r) + 1;
    seg.apply(l-1,r,height);
    cout << height << endl;
  }
  return 0;
}