North America-greater NY 2012__acm_ Game

Reprint please indicate the source, thank http://blog.csdn.net/ACM_cxlove?viewmode=contents by---Cxlove continue to carry forward the good tradition of AK. Everybody says greater NY's problem compares water, really so well. So I am so weak, can only take these several sets of practice practicing.
A: Direct violence, memory
B: Do it directly
C: What is the number of triangles with a perimeter of n? The case is divided into a = B = c, a = B < C, a < b = C, a < b < C, respectively. A bit more complicated is the case of a < b < C, and O (n) enumerates C, and then the number of a + b = n-c & A < b < C is directly introduced. First ignore the conditions of a < B, make a feasible upper and lower bounds, then remove the case of a = B, and divide by 2.
D: This kind of problem is real man. n = 1000, the result is the practice of N ^ 3, a look at the time limit of 2min, frighten cry. Is it meaningful to find Mango ye also discussed the next, no fruit, only n ^ 3 to engage. DP[I][J][K] After I step, current in J, the most right position before the probability of K.
E: Direct high precision violence, write a score class.
F: It seems that I am 2 ^ n * N ^ 2 violent dozen tables.
G: The data range does not give, really real man. Violence BFS, the data range is very small.
H: Little, so direct violence, to find the current point as the center, and all other points of the offset angle, take the smallest.
I: The topic is very long, abandons the cure, maintains the good tradition which the AK cannot.
J: Starting with 0, then the number represents the offset, the example is not over, and then AC, it is really a real man.
code:https://github.com/cxlove/acm_icpc/tree/master/regional/north%20america%20-%20greater%20ny_2012