模拟题目HDU2599

2599 - The Dreadful Seven

时间限制:	Java: 2000 ms / Others: 1000 ms
内存限制:	Java: 32768 KB / Others: 32768 KB

问题描述

Super Mario is studying how to use a mysterious Power Square. The Power Square is n×n with integer values between 0 and n2-1.A number y is a neighbor of another number x in the Power Square if y is directly above or below x, or directly to the left or right
of x. Rosalina asks Super Mario to find all the numbers in the Power Square that are neighbors of the number 7, since she can tell that those numbers are quite nervous.”Why are the numbers scared of seven?” Mario asks Rosalina.”Because seven ate nine!” Rosalina
exclaims.

输入说明

Input is a description of of the Power Square, followed by a number of commands. The first line is the size of the Power Square n. You may assume n<=100. The second line contains the n2 values in the Power Square, separated by spaces. Values start from the
top left corner and move from left to right, moving down one row to the leftmost position when a row is filled.Following the Power Square description are a number of commands, with each command on a separate line. Each command begins with the name of the command,
followed by any additional command parameters.There will no more than 100 commands.

输出说明

The command ”SHOW” causes the current state of the Power Square to be displayed in n × n form (each row of n values on a single line, separated by spaces), followed by a blank line.The command ”NEIGHBORS” is followed by a value x in the Power Square. The values
neighboring x are output and displayed on a single line (in the order: above, left, right, and below x), separated by spaces. You may assume that x is always in the Power Square.

输入样例

3
8 7 6 5 4 3 2 1 0
SHOW
NEIGHBORS 7
NEIGHBORS 1
NEIGHBORS 4
4
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
SHOW
NEIGHBORS 7
NEIGHBORS 1
NEIGHBORS 8
NEIGHBORS 14

输出样例

8 7 6
5 4 3
2 1 0

8 6 4
4 2 0
7 5 3 1
0 1 2 3
4 5 6 7
8 9 10 11
12 13 14 15

3 6 11
0 2 5
4 9 12
10 13 15

杭电OJ平台（代理）

思路：看懂了题意就比较容易想到思路，题目大致意思是当输入show时，就输出矩阵，当输入NEIGHBORS k时就输出k的上下左右数字。

关键是中间的细节处理，总而言之，又是一道看重细节的题目，中间WA了三次，真是过于粗心了。debug点都已经标志出来了。

#include <iostream>
#include <string.h>
using namespace std;

char str[200];
int arr[103][103];
int dir[4][2]={-1,0,0,-1,0,1,1,0};
int n;

void show()
{
int i,j;
for (i=0; i<n; ++i)
{
printf("%d",arr[i][0]); //debug point:first time forget the ' '
for (j=1; j<n; ++j)
{
printf(" %d",arr[i][j]);
}
printf("\n");
}
printf("\n");
}
void neighbor(int m)
{
int i = 0,j = 0,k;
bool isFound = false;
for (i=0; !isFound && i<n; ++i)
{
for (j=0; !isFound && j<n; ++j)
{
if (arr[i][j] == m)
isFound = true;
}
}
--i,--j;
bool isFirstTime = true;
for (k=0; k<4; ++k)
{
if (0 <= i+dir[k][0] && i+dir[k][0] <n && 0 <= j+dir[k][1] && j+dir[k][1] <n)
{
if (!isFirstTime)
printf(" %d",arr[i+dir[k][0]][j+dir[k][1]]); // debug point
else
{
printf("%d",arr[i+dir[k][0]][j+dir[k][1]]);
isFirstTime = false;
}
}
}
puts("");
}
int main()
{
#ifndef ONLINE_JUDGE
freopen("2.txt","r",stdin);
#endif
int i,j,m;
while (scanf("%s",str)!=EOF)
{
if (strcmp(str,"SHOW") && strcmp(str,"NEIGHBORS"))
{
n = atoi(str);
for (i=0; i<n; ++i)
for (j=0; j<n; ++j)
scanf("%d",&arr[i][j]);
getchar();
}
else
{
if (strcmp(str,"SHOW")==0)
show();
else if (strcmp(str,"NEIGHBORS")==0)
{
scanf("%d",&m);
neighbor(m);
}
}
}
return 0;
}