[NOI.AC#34]palinedrome 字符串hash+贪心

容易看出，只要从两边往中间扫描，碰到相等的就直接分割然后加入答案即可,判断相等用字符串hash

#include<bits/stdc++.h>
#define REP(i,a,b) for(int i(a);i<=(b);++i)
#define dbg(...) fprintf(stderr,__VA_ARGS__)
using namespace std;
typedef long long ll;
typedef unsigned int uint;
typedef unsigned long long ull;
template<typename T,typename U>inline char smin(T&x,const U&y){return x>y?x=y,1:0;}
template<typename T,typename U>inline char smax(T&x,const U&y){return x<y?x=y,1:0;}
const int N=1e6+5;
int n;
ull cf[N],hl,hr;
char s[N];
int main(){
	int t;scanf("%d",&t);n=1e5;cf[0]=1;
	REP(i,1,n)cf[i]=cf[i-1]*131;
	while(t--){
		scanf("%s",s+1),n=strlen(s+1);
		int ans=0;hl=hr=0;
		for(int l=1,r=n,p=n;;++l,--r){
			if(l>=r){
				if(l==r||hl!=hr)++ans;
				break;
			}
			hl=hl*131+s[l],hr+=cf[p-r]*s[r];
			if(hl==hr)ans+=2,hl=hr=0,p=r-1;
		}
		printf("%d
",ans);
	}
	return 0;
}