
解题思路
A ( i ) = 1 + 2 + 3 + ⋯ + i A(i) = 1 + 2 + 3 + \dots + i A(i)=1+2+3+⋯+i。
B ( i ) = 1 × 2 × 3 × ⋯ × i B(i) = 1 \times 2 \times 3 \times \dots \times i B(i)=1×2×3×⋯×i。
要使 ( A ( i ) − B ( i ) ) % 100 = 0 (A(i) - B(i)) \% 100 = 0 (A(i)−B(i))%100=0,应当要有