solved by 2sozx Bazoka13 JJLeo
solved by 2sozx
开始是空串,每次操作给出一个字母或者 $-$ 。若为字母则向末尾添加这个字母,否则删除最后一个字符,求每次操作后的回文子串个数。$q\le10000$
考虑暴力算法,维护每个回文串的开头和结尾,串最多 $q^2$ 个,删除时直接删除回文串的末尾为删除位的串,添加时考虑新增的回文串的构成一定是这个字符与前面回文串的组合,特殊考虑仅有 $1,2$ 个字符组成回文串即可。
upsolved by
upsolved by
upsolved by
upsolved by
solved by JJLeo
solved by 2sozx JJLeo
solved by JJLeo
upsolved by
solved by JJLeo