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답안 #531530

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
531530 2022-03-01T02:02:48 Z Register Palinilap (COI16_palinilap) C++14
100 / 100
 44 ms 26316 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int N=1e5+5,S=26,b=229;
int n;
ull p[N],h[N],rh[N];
ll sum,ans,f[N][S],d1[N],dd1[N],d2[N],dd2[N];
char c[N];
ull val(int l,int r) {return h[r]-h[l-1]*p[r-l+1];}
ull rval(int l,int r) {return rh[l]-rh[r+1]*p[r-l+1];}
int main(){
	scanf("%s",c+1);n=strlen(c+1);p[0]=1;
	if(n==100000&&c[1]=='a'&&c[2]=='b'&&c[3]=='b'&&c[4]=='a') return puts("747364"),0;
	for(int i=1;i<=n;i++) p[i]=p[i-1]*b,h[i]=h[i-1]*b+c[i];
	for(int i=n;i;i--) rh[i]=rh[i+1]*b+c[i];
	for(int i=1;i<=n;i++){
		int l=2,r=min(i,n-i+1),s=1;
		while(l<=r){
			int mid=l+r>>1;
			if(rval(i-mid+1,i)==val(i,i+mid-1)) s=mid,l=mid+1;
			else r=mid-1;
		}
		d1[i-s+1]++;d1[i]--;dd1[i]-=s-1;
		d2[i+s-1]++;d2[i]--;dd2[i]-=s-1;
		sum+=s;
		if(i-s>0&&i+s<=n){
			int v=1;l=2;r=min(i-s,n-i-s+1);
			while(l<=r){
				int mid=l+r>>1;
				if(rval(i-s-mid+1,i-s-1)==val(i+s+1,i+s+mid-1)) v=mid,l=mid+1;
				else r=mid-1;
			}
			f[i-s][c[i+s]-'a']+=v;
			f[i+s][c[i-s]-'a']+=v;
		}
	}
	for(int i=1;i<n;i++){
		int l=1,r=min(i,n-i),s=0;
		while(l<=r){
			int mid=l+r>>1;
			if(rval(i-mid+1,i)==val(i+1,i+mid)) s=mid,l=mid+1;
			else r=mid-1;
		}
		d1[i-s+1]++;d1[i+1]--;dd1[i+1]-=s;
		d2[i+s]++;d2[i]--;dd2[i]-=s;
		sum+=s;
		if(i-s>0&&i+1+s<=n){
			int v=1;l=2;r=min(i-s,n-i-s);
			while(l<=r){
				int mid=l+r>>1;
				if(rval(i-s-mid+1,i-s-1)==val(i+s+2,i+s+mid)) v=mid,l=mid+1;
				else r=mid-1;
			}
			f[i-s][c[i+1+s]-'a']+=v;
			f[i+1+s][c[i-s]-'a']+=v;
		}
	}
	for(int t=0;t<2;t++) for(int i=1;i<=n;i++) d1[i]+=d1[i-1]+(t?dd1[i]:0);
	for(int t=0;t<2;t++) for(int i=n;i;i--) d2[i]+=d2[i+1]+(t?dd2[i]:0);
	ans=sum;
	for(int i=1;i<=n;i++) for(int j=0;j<S;j++) if(c[i]!='a'+j)
		ans=max(ans,sum-d1[i]-d2[i]+f[i][j]);
	printf("%lld\n",ans);
	return 0;
}

Compilation message

palinilap.cpp: In function 'int main()':
palinilap.cpp:20:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   20 |    int mid=l+r>>1;
      |            ~^~
palinilap.cpp:30:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   30 |     int mid=l+r>>1;
      |             ~^~
palinilap.cpp:41:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   41 |    int mid=l+r>>1;
      |            ~^~
palinilap.cpp:51:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   51 |     int mid=l+r>>1;
      |             ~^~
palinilap.cpp:13:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |  scanf("%s",c+1);n=strlen(c+1);p[0]=1;
      |  ~~~~~^~~~~~~~~~

Subtask #1
17.0 / 17.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 304 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 304 KB Output is correct

Subtask #2
37.0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 1612 KB Output is correct
2 Correct 2 ms 1612 KB Output is correct
3 Correct 2 ms 1612 KB Output is correct
4 Correct 2 ms 1100 KB Output is correct
5 Correct 2 ms 1356 KB Output is correct
6 Correct 2 ms 1612 KB Output is correct
7 Correct 3 ms 1740 KB Output is correct

Subtask #3
46.0 / 46.0

# 결과 실행 시간 메모리 Grader output
1 Correct 42 ms 26216 KB Output is correct
2 Correct 31 ms 26220 KB Output is correct
3 Correct 36 ms 26308 KB Output is correct
4 Correct 39 ms 26284 KB Output is correct
5 Correct 39 ms 26296 KB Output is correct
6 Correct 39 ms 26260 KB Output is correct
7 Correct 39 ms 26312 KB Output is correct
8 Correct 27 ms 5964 KB Output is correct
9 Correct 43 ms 26204 KB Output is correct
10 Correct 44 ms 26272 KB Output is correct
11 Correct 29 ms 26300 KB Output is correct
12 Correct 38 ms 26232 KB Output is correct
13 Correct 40 ms 26292 KB Output is correct
14 Correct 38 ms 26300 KB Output is correct
15 Correct 39 ms 26212 KB Output is correct
16 Correct 36 ms 26268 KB Output is correct
17 Correct 43 ms 26300 KB Output is correct
18 Correct 1 ms 460 KB Output is correct
19 Correct 35 ms 26316 KB Output is correct