Python解决codeforces ---- 4

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概述

第一题 10A

Tom is interested in power consumption of his favourite laptop. His laptop has three modes. In normal mode laptop consumesP1watt per minute.T1minutes after Tom moved the mouse or touched the keyboard for the last time, a screensaver starts and power consumption changes toP2watt per minute. Finally, afterT2minutes from the start of the screensaver, laptop switches to the "sleep" mode and consumesP3watt per minute. If Tom moves the mouse or touches the keyboard when the laptop is in the second or in the third mode, it switches to the first (normal) mode. Tom's work with the laptop can be divided intontime periods[l1, r1], [l2, r2], ..., [ln, rn]. During each interval Tom continuously moves the mouse and presses buttons on the keyboard. Between the periods Tom stays away from the laptop. Find out the total amount of power consumed by the laptop during the period[l1, rn].

Input

The first line contains 6 integer numbersn,P1,P2,P3,T1,T2(1 ≤ n ≤ 100, 0 ≤ P1, P2, P3 ≤ 100, 1 ≤ T1, T2 ≤ 60). The followingnlines contain description of Tom's work. Eachi-th of these lines contains two space-separated integersliandri(0 ≤ li < ri ≤ 1440,ri < li + 1fori < n), which stand for the start and the end of thei-th period of work.

Output

Output the answer to the problem.

Sample test(s)

input
1 3 2 1 5 10
0 10

output
30

input
2 8 4 2 5 10
20 30
50 100

output
570

题意：电脑有三种模式，正常模式每分钟耗电p1，如果没有使用电脑t1分钟后变成第二种模式每分钟耗电p2，如果还是没有使用电脑t2分钟后变成第三种模式每分钟耗电p3。给定n个区间，每一个区间是正常模式，每个区间的间隔是没有使用，问总的耗电是多少

思路：直接暴力枚举

代码：

# input
list = raw_input().split()
n,p1,p2,t1,t2,t3 = map(int , list)
# solve
ans = 0
pre = -1
while n > 0:
n -= 1
list = raw_input().split()
start,end = map(int , list)
ans += (end-start)*p1
if pre != -1:
x = start-pre
if x > t1:
ans += t1*p1
x -= t1
if x > t2:
ans += t2*p2
x -= t2
ans += x*p3
else:
ans += x*p2
else:
ans += x*p1
pre = end
print ans

第二题 11A

A sequencea0, a1, ..., at - 1is called increasing ifai - 1 < aifor eachi: 0 < i < t.

You are given a sequenceb0, b1, ..., bn - 1and a positive integerd. In each move you may choose one element of the given sequence and adddto it. What is the least number of moves required to make the given sequence increasing?

Input

The first line of the input contains two integer numbersnandd(2 ≤ n ≤ 2000, 1 ≤ d ≤ 106). The second line contains space separated sequenceb0, b1, ..., bn - 1(1 ≤ bi ≤ 106).

Output

Output the minimal number of moves needed to make the sequence increasing.

Sample test(s)

input
4 2
1 3 3 2

output
3

题意：给定n个数的序列，现在要把这个序列变成递增的序列，满足ai < ai+1，现在规定每次可以选择一个数来增加d，问最少需要几次

思路：枚举每一个数求个数即可

代码：

# input
n,d = map(int , raw_input().split())
list = map(int , raw_input().split())
# getAns
ans = 0
for i in range(1,len(list)):
if list[i] <= list[i-1]:
x = (list[i-1]-list[i])/d+1
list[i] += x*d
ans += x
print ans

第三题 12A

There is a very secret base in Potatoland where potato mash is made according to a special recipe. The neighbours from Porridgia decided to seize this recipe and to sell it to Pilauland. For this mission they have been preparing special agent Pearlo for many years. When, finally, Pearlo learned all secrets of espionage, he penetrated into the Potatoland territory and reached the secret base.

Now he is standing at the entrance, but to get inside he need to pass combination lock. Minute ago one of the workers entered the password on the terminal and opened the door. The terminal is a square digital keyboard3 × 3with digits from1to9.

Pearlo knows that the password consists from distinct digits and is probably symmetric with respect to the central button of the terminal. He has heat sensor which allowed him to detect the digits which the worker pressed. Now he wants to check whether the password entered by the worker is symmetric with respect to the central button of the terminal. This fact can Help Pearlo to reduce the number of different possible password combinations.

Input

Input contains the matrix of three rows of three symbols each. Symbol «X» means that the corresponding button was pressed, and «.» means that is was not pressed. The matrix may contain no «X», also it may contain no «.».

Output

PrintYESif the password is symmetric with respect to the central button of the terminal andNOotherwise.

Sample test(s)

input
XX.
...
.XX

output
YES

input
X.X
X..
...

output
NO

Note

If you are not familiar with the term «central symmetry», you may look into http://en.wikipedia.org/wiki/Central_symmetry

题意：给定一个3*3的矩形，每个元素不是X就是.，问这个矩形是否是对称的

思路：暴力枚举每一个点，然后判断每个点是否和它的对称点都相等即可

代码：

# input
matrix = []
for i in range(3):
matrix.append(raw_input())
# solve
def isOk():
for i in range(3):
for j in range(3):
x = 2-i
y = 2-j
if matrix[i][j] != matrix[x][y]:
return False
return True
# ouput
if isOk():
print "YES"
else:
print "NO"