HDU1001 for implicit type conversion of the accumulate formula, hdu1001 accumulate Formula

HDU1001 for implicit type conversion of the accumulate formula, hdu1001 accumulate Formula

HDU 1001 is stuck.

Inspired by Xiao Bai, such cycle problems are directly converted into formulas for solving to optimize the time. But! I just can't go through it!

Problem code:

# Include <stdio. h> int main () {int a; while (scanf ("% d", & )! = EOF) printf ("% d \ n", a * (1 + a)/2); return 0 ;}

The problem is that although the question indicates that the final result will be within 32 bits, there is no guarantee that a * (1 + a) is also 32bit ....... cainiao ignores the implicit type conversion before Division, resulting in the result being 0 when the data size is appropriate .......

This is over .......

# Include <stdio. h> int main () {long a; while (scanf ("% lld", & )! = EOF) printf ("% lld \ n", a * (1 + a)/2); return 0 ;}