During the War of Resistance Against Japan, tunnel warfare was carried out extensively in the vast areas of north China Plain. Generally speaking, villages connected by tunnels lay in a line. Except the two at the ends, every village was directly connected with two neighboring ones.
During the War of Resistance Against Japan,
阅读背景：
Tunnel Warfare HDU - 1540 单点更新 区间合并 线段树
来源：互联网
分享到：
