POJ2941 SDUT2371Homogeneous squares

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 1 #include<stdio.h>
 2 #include<string.h>
 3 int main()
 4 {
 5     long i,j,n,g,s,t,a[1001],b[1001];
 6     char str[8001];//这里数组开大一点 第一次RT了 数比较大
 7     while(scanf("%ld", &n)&&n)
 8     {
 9         s = 0;
10         t = 0;
11         int flag = 1;
12         scanf("%d", &a[0]);
13         for(i = 1 ; i < n ; i++)
14             {
15                 scanf("%ld",&a[i]);
16                 b[i] = a[i]-a[i-1];
17             }
18         for(g = 2 ; g <= n ; g++)
19         {                
20             scanf("%d", &a[0]);            
21             for(j = 1  ;j < n ; j++)
22             {
23                 scanf("%d", &a[j]);
24                 if(b[j]!=a[j]-a[j-1])
25                 {
26                     flag = 0;
27                     goto in;
28                 }
29             }
30         }
31 in:{
32        for(i = g ; i <= n  ;i++)
33            gets(str);
34    }
35         if(flag == 1)
36             printf("homogeneous\n");
37         else
38             printf("not homogeneous\n");
39     }
40     return 0;
41 }

这个题很容易TLE 从网上搜了下题解 找了篇比较好的 自己按照思想敲了一遍 搬这里了 也忘记出处了 就不贴原创了

Homogeneous squares

Time Limit: 1000MS Memory limit: 65536K

题目描述

Assume you have a square of size n that is divided into n×n positions just as a checkerboard. Two positions (x₁,y₁) and (x₂,y₂), where 1 ≤ x₁,y₁,x₂,y₂ ≤ n, are called "independent" if they occupy different rows and different columns, that is, x₁≠x₂ and y₁≠y₂. More generally, n positions are called independent if they are pairwise independent. It follows that there are n! different ways to choose n independent positions.

Assume further that a number is written in each position of such an n×n square. This square is called "homogeneous" if the sum of the numbers written in n independent positions is the same, no matter how the positions are chosen. Write a program to determine if a given square is homogeneous!

输入

The input contains several test cases. 
The first line of each test case contains an integer n (1 ≤ n ≤ 1000). Each of the next n lines contains n numbers, separated by exactly one space character. Each number is an integer from the interval [-1000000,1000000]. 
The last test case is followed by a zero.

输出

For each test case output whether the specified square is homogeneous or not. Adhere to the format shown in the sample output.

示例输入

2

1 2

3 4

3

1 3 4

8 6 -2

-3 4 0

0

示例输出

homogeneous

not homogeneous