HDU1868:Consecutive sum
Problem Description Every body knew that 15 = 1+2+3+4+5 = 4+5+6 = 7+8. Now gi
BZOJ 1076([SCOI2008]獎勵關-期望dp-從後向前)
1076: [SCOI2008]獎勵關 Time Limit: 10 Sec Memory Limit: 162 MB Submit: 328
Poj 2284 Hoj 1890 That Nice Euler Circuit
本題用到平面圖的歐拉公式:設平面圖的頂點數、邊數和面數分別為V,E,F,則V+F-E=2. 1.在求頂點數V的時候,很容易想到的想法是判斷線段兩兩相交,如