#include <bits/stdc++.h> #define FOR(i, beg, ed, etr) for(ll i = beg;i <= ed;i += etr) #define FORN(i, beg, ed, etr) for(ll i = beg;i >= ed;i -= etr) #define all(x) x.begin(), x.end() #define F first #define pb push_back #define S second #define con continue using namespace std; typedef long long ll; typedef pair<ll,ll> pii; typedef pair<ll,ll> pll; typedef double db; typedef long double ld; //qwertqetqer const ll inf = 1e9; const ll INF = 1e18; const ll N = 5e5 + 5; const ll MOD = 1e9 + 7; ll a[N],pre[N]; int n; struct node{ ll pre,suf,sum,ans; node operator+(node b){ node ret; ret.pre = max(pre, sum + b.pre); ret.suf = max(suf + b.sum, b.suf); ret.sum = sum + b.sum; ret.ans = max(max(ans+b.sum, sum + b.ans), pre + b.suf); return ret; } }; node t[4 * N]; void build(int v = 1,int l = 1,int r = n){ if(l == r){ if(a[l] == 1)t[v] = {1,1,1,1}; else t[v] = {0,0,-1,0}; return; } int mid = (l + r) / 2; build(v+v,l,mid); build(v+v+1,mid+1,r); t[v] = (t[v+v] + t[v+v+1]); } node get(int ql,int qr,int v = 1,int l = 1,int r= n){ if(ql <= l && r <= qr){ return t[v]; } if(r < ql || qr < l)return {0,0,0,0}; int mid = (l + r) / 2; return (get(ql,qr,v+v,l,mid) + get(ql,qr,v+v+1,mid+1,r)); }; void solve(){ cin >> n; FOR(i, 1, n, 1){ char c;cin >> c; if(c == 'C')a[i] = -1; else a[i] = 1; pre[i] = pre[i-1] + a[i]; } build(); int q;cin >> q; while(q--){ int l,r;cin >> l >> r; node res = get(l,r); cout << res.ans << '\n'; } } main(){ ios_base::sync_with_stdio(0); cin.tie(0); // freopen("optmilk.in","r",stdin); // freopen("optmilk.out","w",stdout); ll abd = 1; // cin >> abd; FOR(i, 1, abd, 1){ solve(); } }

election.cpp:70:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   70 | main(){
      | ^~~~