1 #include<iostream> 2 using namespace std; 3 #define ios_base \ 4 ios::sync_with_stdio(false);\ 5 cin.tie(nullptr);\ 6 cout.tie(nullptr) 7 const int N = 1e5+10; 8 int n,k;//cnt[]用来计数不同余数的出现次数 9 long long a[N],cnt[N];//cnt[]的下标可不只有0~9这么简单,举个例子:999%9999,保险起见还是开long long cnt[],而a[]要作为前缀和数组所以也要开大点 10 long long res=0; 11 int main() 12 { 13 ios_base; 14 cin>>n>>k; 15 for (int i = 1; i <= n; i++) 16 { 17 cin>>a[i]; 18 a[i]+=a[i-1];//构建前缀和数组 19 } 20 cnt[0]++; 21 for (int i = 1; i <= n; i++) 22 { 23 res+=cnt[a[i]%k]; 24 cnt[a[i]%k]++; 25 } 26 cout<<res<<'\n'; 27 28 return 0; 29 }
标签:cnt,前缀,int,ios,long,区间,tie From: https://www.cnblogs.com/shinnyblue/p/17243063.html