#include iostreamusing namespace std;int main(){ int n; cinn; int s=0,ans=0; for(int i=1;i=n;i++){ s+=i; ans+=s; } coutans; return 0;}

点我呐

#include iostreamusing namespace std;int main(){ int a,b,c,d; cinabcd; int t1=a*60+b; int t2=c*60+d; coutt2-t1; return 0;}

点我呐