qq_41854014的博客

离散化+前缀和.#include<bits/stdc++.h>using namespace std;const int maxn = 1e8+5;int l[maxn] = {0};int main(int argc, char const *argv[]){ std::ios::sync_with_stdio(false); l[0] = 1; int len, m; scanf("%d%d",&len,&m); for (int i = 0;