480 - 暑訓練習 (2013/08/01) ICPC 2008 Dhaka Scoreboard

Time

2013/08/01 12:25:00 2013/08/01 17:25:00

Clarification

# Problem Asker Description Reply Replier Reply Time For all team

3226 - John's trip   

3227 - Catenyms   

Description

 http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=1919

Input

Output

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Sample Output  Download

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3228 - The Necklace   

3229 - Getting in Line   

3230 - Task Sequences   

3231 - Nearest Common Ancestors   

Description

 http://poj.org/problem?id=1330

Input

Output

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Sample Output  Download

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3232 - Fence Repair   

Description

 http://poj.org/problem?id=3253

Input

Output

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Sample Output  Download

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3233 - (*) Find the Format String   

3234 - (*) Switch Bulbs   

3235 - (*) Schedule of a Married Man   

3236 - (*) Puzzles of Triangles   

3237 - (*) Chemical Plant   

3238 - (*) Clicking Checkboxes   

3239 - (*) Magic Rings   

3240 - (*) Line Chart   

3241 - (*) Mobile Tower   

3242 - (*) Stopping Doom's Day   

7432 - Error Correction   

Description

A boolean matrix has the parity property when each row and each column has an even sum, i.e. contains an even number of bits which are set. Here's a 4 x 4 matrix which has the parity property:
1 0 1 0
0 0 0 0
1 1 1 1
0 1 0 1
The sums of the rows are 2, 0, 4 and 2. The sums of the columns are 2, 2, 2 and 2.
Your job is to write a program that reads in a matrix and checks if it has the parity property. If not, your program should check if the parity property can be established by changing only one bit. If this is not possible either, the matrix should be classified as corrupt.

Input

The input file will contain one or more test cases. The first line of each test case contains one integer n (n<100), representing the size of the matrix. On the next n lines, there will be n integers per line. No other integers than 0 and 1 will occur in the matrix. Input will be terminated by a value of 0 for n.

Output

For each matrix in the input file, print one line. If the matrix already has the parity property, print "OK". If the parity property can be established by changing one bit, print "Change bit (i,j)" where i is the row and j the column of the bit to be changed. Otherwise, print "Corrupt".

Sample Input  Download

Sample Output  Download

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