Invert

input/code.cpp: In member function 'void sumsegtree::initfrom(std::vector<long long int>)':
input/code.cpp:23:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(n < a.size())
                    ^
input/code.cpp:28:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < a.size(); i++)
                             ^

#include <bits/stdc++.h>

#define i64 long long
#define u64 unsigned long long
#define i32 int
#define u32 unsigned int

#define pii pair<int, int>
#define pll pair<long long, long long>

#define ld long double
#define defmod 1000000007
#define ll long long
#define mati64(a,b) vector<vector<i64>>(a, vector<i64>(b, 0));
using namespace std;

struct sumsegtree{
	vector<ll> p;
	vector<ll> ad;
	ll n = 1;
	
	void initfrom(vector<ll> a){
		while(n < a.size())
			n*=2;
		
		p = vector<ll>(2*n, 0);
		ad = vector<ll>(2*n, 0);
		for(int i = 0; i < a.size(); i++)
			p[i+n] = a[i];
		for(int i = n-1; i >= 0; i--)
			p[i] = p[i*2]+p[i*2+1];

	}

	void init(int nn){
		while(n < nn)
			n*=2;
		p = vector<ll>(2*n, 0);
		ad = vector<ll>(2*n, 0);
	}

	void add2(int idx, int a, int b, int l, int r, ll x){
		if(a >= r || b <= l)
			return;
		else if(a >= l && b <= r){
			ad[idx]+=x;
			p[idx]+=(b-a)*x;
		}
		else{
			int m = (a+b)/2;
			add2(idx*2, a, m, l, r, x);
			add2(idx*2+1, m, b, l, r, x);
			p[idx] = p[idx*2]+p[idx*2+1]+(b-a)*ad[idx];
		}
	}
	//closed range -> closed-open
	void add(int l, int r, ll x){
		add2(1, 0, n, l, r+1, x);
	}
	ll querysum2(int idx, int a, int b, int l, int r, i64 ad2){
		if(a >= r || b <= l)
			return 0;
		else if(a >= l && b <= r){
			return p[idx]+(b-a)*ad2;
		}
		else{
			int m = (a+b)/2;
			return querysum2(idx*2, a, m, l, r, ad2+ad[idx])+querysum2(idx*2+1, m, b, l, r, ad2+ad[idx]);
		}
	}
	//closed range -> closed-open
	ll querysum(int l, int r){
		return querysum2(1, 0, n, l, r+1, 0);
	}

};
int main(){
	cin.sync_with_stdio(0);
	cin.tie(0);
	
	int q; cin >> q;
	sumsegtree lol;
	lol.init(100010);

	i64 inv = 0;
	while(q--){
		int typ; cin >> typ;
		if(typ == 1){
			int a; cin >> a;
			if(a != 100000)
				inv+=lol.querysum(a+1, 100000);
			lol.add(a, a, 1);
		}
		else if(typ == 2){
			
			int a; cin >> a;
			if(a != 1)
				inv+=lol.querysum(1, a-1);
			lol.add(a, a, 1);
		}
		else if(typ == 3){
			inv = 0;
		}
		else if(typ == 4){
			cout << inv << endl;
		}
	}
	return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED