Codeforces Round #385 (Div. 2), problem: (E) Hongcow Buys a Deck of Cards Solution in C/C++

#include<bits/stdc++.h>
using namespace std;

const int maxn=16,INF=0x3f3f3f3f;
char type[maxn];
int R[maxn],B[maxn];

char readchar() {
	for(;;) {
		char ch=getchar();
		if(!isspace(ch)) {
			return ch;
		}
	}
}

int n;

typedef pair<int,int> pii;
typedef set<pii> Spii;
Spii dp[1<<maxn];

void Insert(Spii& s,const pii& p) {
	Spii::iterator it=s.lower_bound(p);
	if(it==s.begin()||(--it)->second>p.second) {
		s.insert(p);
		it=s.upper_bound(p);
		while(it!=s.end()&&it->second>=p.second) {
			s.erase(it++);
		}
	}
}

void DP(int s) {
	Spii& res=dp[s];
	if(res.size()) {
		return;
	}
	if(s==0) {
		res.insert(make_pair(0,0));
		return;
	}
	int curR=0,curB=0;
	for(int i=0;i<n;i++) {
		if(!((s&(1<<i)))) {
			if(type[i]=='R') {
				curR++;
			} else {
				curB++;
			}
		}
	}
	for(int i=0;i<n;i++) {
		if(s&(1<<i)) {
			DP(s&(~(1<<i)));
			Spii& tmp=dp[s&(~(1<<i))];
			for(Spii::iterator it=tmp.begin();it!=tmp.end();it++) {
				Insert(res,make_pair(it->first+max(0,R[i]-curR),it->second+max(0,B[i]-curB)));
			}
		}
	}
}

int main() {
	cin>>n;
	for(int i=0;i<n;i++) {
		type[i]=readchar();
		cin>>R[i]>>B[i];
	}
	DP((1<<n)-1);
	int ans=INF;
	Spii& res=dp[(1<<n)-1];
	for(Spii::iterator it=res.begin();it!=res.end();it++) {
		ans=min(ans,max(it->first,it->second)+n);
	}
	cout<<ans<<endl;
	return 0;
}