2023 rcpc

2023/rcpc/d1/editorial/G. Sign Flipping.cpp

@@ -0,0 +1,32 @@
+/// Gheorghies Alexandru
+#include<bits/stdc++.h>
+
+using namespace std;
+typedef long long ll;
+typedef pair<ll,ll> pll;
+const ll NMAX=3e5+5,LGMAX=17;
+ll v[NMAX];
+map<ll,ll> fr,prv;
+int main()
+{
+    #ifndef ONLINE_JUDGE
+        freopen("in.txt","r",stdin);
+        freopen("out.txt","w",stdout);
+    #endif
+    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
+    ll n,ans=0;
+    cin>>n;
+    for(ll i=1;i<=n;i++){
+        cin>>v[i];
+        v[i]=abs(v[i]);
+        ++fr[v[i]];
+        if(fr[v[i]]%2) v[i]=-v[i];
+    }
+    for(ll i=1;i<=n;i++){
+        ans+=(i-prv[v[i]])*(n-i+1);
+        prv[v[i]]=i;
+    }
+    cout<<ans;
+    return 0;
+}
+