摘要:
存一发模板233 #include<cstdio> #include<iostream> #include<cstdlib> #include<cstring> #include<algorithm> #include<queue> #include<vector> #include<ctime> 阅读全文
摘要:
"题目链接" problem 给出两个长度为n的数列a,b。求一个数列c满足:$$c[k] = \sum\limits_{i = k} ^ na[i]b[i k]$$ $n\le 10^5$ solution 长得和卷积很像,观察一下卷积的形式:$c[k]=\sum\limits_{i=0}^ia[ 阅读全文