HDU-1391 Number Steps

http://acm.hdu.edu.cn/showproblem.php?pid=1391

Number Steps

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 3280    Accepted Submission(s): 2030

Problem Description

Starting from point (0,0) on a plane, we have written all non-negative integers 0, 1, 2,... as shown in the figure. For example, 1, 2, and 3 has been written at points (1,1), (2,0), and (3, 1) respectively and this pattern has continued.You are to write a program that reads the coordinates of a point (x, y), and writes the number (if any) that has been written at that point. (x, y) coordinates in the input are in the range 0...5000.

 

Input

The first line of the input is N, the number of test cases for this problem. In each of the N following lines, there is x, and y representing the coordinates (x, y) of a point.

 

Output

For each point in the input, write the number written at that point or write No Number if there is none.

 

Sample Input

3

4 2

6 6

3 4

 

Sample Output

6

12

No Number

 

Source

Asia 2000, Tehran (Iran)

 

Recommend

//看图找规律。x与y的关系。。。
#include<stdio.h>
int main()
{
 int T,x,y;
 scanf("%d",&T);
 while(T--)
 {
  scanf("%d%d",&x,&y);
  if(x!=y&&y+2!=x)
  {
   printf("No Number\n");
  }
  else if(x==y)
  {
   if(x%2==0)
    printf("%d\n",x+y);
   else
    printf("%d\n",x+y-1);
  }
  else
  {
    if(x%2==0)
    printf("%d\n",2*x-2);
   else
    printf("%d\n",2*x-3);
  }
 }
 return 0;
}