Submission #531523

# Submission time Handle Problem Language Result Execution time Memory
531523 2022-03-01T01:52:47 Z Register Palinilap (COI16_palinilap) C++14
54 / 100
43 ms 26392 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;
	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:19:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   19 |    int mid=l+r>>1;
      |            ~^~
palinilap.cpp:29:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   29 |     int mid=l+r>>1;
      |             ~^~
palinilap.cpp:40:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   40 |    int mid=l+r>>1;
      |            ~^~
palinilap.cpp:50:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   50 |     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;
      |  ~~~~~^~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 3 ms 1580 KB Output is correct
2 Correct 2 ms 1612 KB Output is correct
3 Correct 2 ms 1612 KB Output is correct
4 Correct 1 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 2 ms 1612 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 40 ms 26292 KB Output is correct
2 Correct 30 ms 26228 KB Output is correct
3 Correct 30 ms 26248 KB Output is correct
4 Correct 42 ms 26392 KB Output is correct
5 Correct 40 ms 26296 KB Output is correct
6 Correct 40 ms 26316 KB Output is correct
7 Correct 38 ms 26208 KB Output is correct
8 Correct 20 ms 5936 KB Output is correct
9 Correct 40 ms 26180 KB Output is correct
10 Correct 38 ms 26260 KB Output is correct
11 Correct 29 ms 26268 KB Output is correct
12 Correct 43 ms 26244 KB Output is correct
13 Correct 43 ms 26280 KB Output is correct
14 Correct 40 ms 26304 KB Output is correct
15 Correct 39 ms 26264 KB Output is correct
16 Correct 35 ms 26264 KB Output is correct
17 Correct 36 ms 26260 KB Output is correct
18 Incorrect 38 ms 26300 KB Output isn't correct
19 Halted 0 ms 0 KB -