摘要： #include"iostream"#include"cstdlib“using namespace std;int main(){ long long i; long long A[100000000]={1,3,6,10,15,21,28,36,45,55,66,78,91,105,120,136,153,171,190,210,231,253,276,300,325,351,378,406,435,465,496,528,561,595,630,666,703,741,780,820,861,903,946,990,1035,1081,1128,1176,1 阅读全文