C language notes: Saddle Point Problems

Original link: http://c.biancheng.net/c/

Problem Description:
a m * n (1 <n and m <= 10) matrix, each matrix row there is only one maximum value, a minimum value for each column only requires the matrix to find the saddle point. What is a saddle point? I.e., a matrix element, that is the maximum value of the row, where the column is the minimum . If the required output saddle point coordinates and its value, if there is no output saddle point "no saddle point"

Solutions:

Make a first outer loop, the line number from the beginning row, row line to find the maximum element a [row] [col], col row for the first row under the column numbers where the largest element
Then followed to see if the element has respective col column is smaller than a [row] [col] of
Subsequently not found or determined in accordance with a further found

Code:

#include <stdio.h>
const int N=11;
int AnDian(int a[N][N],int n,int m,int *r,int *c);//在n*m数组中找鞍点，如果找到用*r,*c存放鞍点行号、列号，返回1；否则返回0 
int main(void)
{
 int a[N][N],r,c;//r,c分别存放鞍点的行号和列号 
 int n,m;
 printf("输入n m：\n");
 scanf("%d %d",&n,&m);
 printf("接着输入n*m个矩阵元素：\n");
 for(int i=1;i<=n;i++)
 {
  for(int j=1;j<=m;j++)
  {
   scanf("%d",&a[i][j]);
  }
 }
 int res=AnDian(a,n,m,&r,&c);
 if(res)
 {
  printf("鞍点元素下标，以及元素值为：");
  printf("（%d，%d） %d\n",r,c,a[r][c]);
 }
 else
 {
  printf("not found!\n");
 }
 return 0;
}
int AnDian(int a[N][N],int n,int m,int *r,int *c)
{
 int flag=0;//0表示没找到，1表示找到，初始化未找到 
 for(int row=1;row<=n;row++)//该层循环用于控制指向矩阵的行数 
 {
  int col=1;//假设row行的第1列元素是row行的最大元素 
  int j;//①用于控制第一个内层for循环次数 以及 ②判断是否完全循环完第二个内层for循环次数
  for(j=2;j<=m;j++)//用于找出row行的最大元素的col下标，col随着元素的增大不断更新 
  {
   if(a[row][j]>a[row][col])
   {
    col=j;
   }
  }
  for(j=1;j<=n;j++)//将该col下标元素与其上下行元素比较，看是否是第col列最小元素 
  {
   if(a[j][col]<a[row][col])
   {
    break;//若没有提前退出当前循环（此时j==n+1），则a[row][col]是第col最小元素 
   }
  }
  if(j==n+1)
  {
   flag=1;
   *r=row;
   *c=col; 
   break;
  }
 } 
 return flag; 
}

Output:
Here Insert Picture Description
I found in doing the program can only return to the saddle point of the first found, and its index, but a few carefully thought matrix (matrix and have more repeat elements), we found only one saddle point or to a nor both cases, God can see the big explain it? Or a matrix can have multiple saddle points but I did not expect. headache!

C language notes: Saddle Point Problems

Guess you like