#include<iostream>
#include<stack>
#include<map>
#include<vector>
#include<string>
#include<cassert>
#include<unordered_map>
#include <queue>
#include <cstdint>
#include<cstring>
#include<limits.h>
#include<cmath>
#include<set>
#include<algorithm>
#include <iomanip>
#include<numeric>
#include<bitset>
using namespace std;
#define ll long long
#define f first
#define s second
#define pii pair<int,int>
#define ppii pair<int,pii>
#define vi vector<int>
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define F(n) for(int i=0;i<n;i++)
#define lb lower_bound
#define ub upper_bound
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
#pragma GCC optimize ("03,unroll-lopps")
#define int long long
#define double long double
using namespace std;
const int mod=1e9+7,mxn=5e3+5,inf=1e18,minf=-1e18,lg=30;
//#undef int
int n,k,m,x,q;
void setIO(string name){
ios_base::sync_with_stdio(0); cin.tie(0);
freopen((name+".in").c_str(),"r",stdin);
freopen((name+".out").c_str(),"w",stdout);
}
vector<int>A,B;
int prefB[mxn+10];
int pref[mxn+10],cntA[mxn+10];
int getcost(int l,int r){
l--,r--;
return (pref[A[r]]-pref[max(A[l],B[l])-1])-(cntA[A[r]]-cntA[max(A[l],B[l])-1])*(prefB[B[l]-1]);
}
int dp[mxn+10][mxn+10];
void dc(int l,int r,int optl,int optr,int k){
if(r<l)return;
int mid=l+(r-l)/2;
pii ans={inf,n};
for(int i=optl;i<=min(optr,mid-1);i++){
ans=min(ans,make_pair(dp[i][k-1]+getcost(i+1,mid),i));
}
dp[mid][k]=ans.f;
dc(l,mid-1,optl,ans.s,k);
dc(mid+1,r,ans.s,optr,k);
}
int32_t main(){
fastio
cin>>n>>k;
string a;cin>>a;
int c=0;
for(int i=1;i<=2*n;i++){
if(a[i-1]=='A')A.pb(i),cntA[i]++;
else B.pb(i),c++;
prefB[i]=c;
if(a[i-1]=='A')pref[i]=prefB[i];
pref[i]+=pref[i-1],cntA[i]+=cntA[i-1];
}
for(int i=0;i<=k;i++)for(int j=1;j<=n;j++)dp[j][i]=inf;
dp[0][0]=0;
for(int i=1;i<=k;i++){
dc(1,n,0,n,i);
}
cout<<dp[n][k];
/*
L=j,
dp[i][k] = dp[j][k-1] + (pref[AR]-pref[BL]) - (cntA[AR]-cntA[BL])*(prefB[BL-1]);
dp[j][k-1] + sum of (cnt of Bj Ai where j<i) in range (first B , last A)
- (cnt of A in range [firsB,last A])*(cnt of Bj<BL)
*/
}
컴파일 시 표준 에러 (stderr) 메시지
chorus.cpp:32:40: warning: bad option '-funroll-lopps' to pragma 'optimize' [-Wpragmas]
32 | #pragma GCC optimize ("03,unroll-lopps")
| ^
chorus.cpp:39:23: warning: bad option '-funroll-lopps' to attribute 'optimize' [-Wattributes]
39 | void setIO(string name){
| ^
chorus.cpp:47:24: warning: bad option '-funroll-lopps' to attribute 'optimize' [-Wattributes]
47 | int getcost(int l,int r){
| ^
chorus.cpp:52:44: warning: bad option '-funroll-lopps' to attribute 'optimize' [-Wattributes]
52 | void dc(int l,int r,int optl,int optr,int k){
| ^
chorus.cpp:63:14: warning: bad option '-funroll-lopps' to attribute 'optimize' [-Wattributes]
63 | int32_t main(){
| ^
chorus.cpp: In function 'void setIO(std::string)':
chorus.cpp:41:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
41 | freopen((name+".in").c_str(),"r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
chorus.cpp:42:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
42 | freopen((name+".out").c_str(),"w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |