CodeForces 622A Infinite Sequence

等差数列问题

#include <iostream>#include <cstdio>int main(){__int64 n;scanf("%I64d", &n);__int64 i = 1;while (i * (1 + i) / 2 < n){++i;}__int64 tmp = (i - 1) * i / 2;//std::cout << tmp << std::endl;printf("%I64d\n", n - tmp);return 0;}