c - 为什么这个程序无法在(4*4)(或更高)数组中找到鞍点？

Question

  #include <stdio.h>

  int main(void)
  {
     int n, m, i, j, k, q, r, maxr = 0, state = 0, count= 0;
     puts("Enter two numbers represents two dimensional array, N * M");
     puts("This program will find the saddle points");
     scanf("%d %d", &n, &m);
     int ar[n][m];
     for (j = 0; j < m; j++)
    {
    for (i = 0; i < n; i++)
    {
        puts("Enter the number in array");
        scanf("%d", &ar[i][j]);     //store the number form user
        printf("Array accepted %d, and this number's location is [%d][%d]\n", ar[i][j], i, j);
    }
}
    for (int j = 0; j < m; j++) //print the two dimensional array
    {
        for (int i = 0; i < n; i++)
        {
           printf("%3d", ar[i][j]);
        }
    putchar('\n');
   }


    for (int j = 0; j < n; j++)   //find the saddle point
    {
        for (int i = 0; i < m; i++)
        {   
            if(ar[i][j] > maxr)     //compare the number is i row until find the biggest
            {
                maxr = ar[i][j];
                q = i;
                r = j;
            }
            else
               continue;
    }

    for (int k = 0; k < n; k++)
    {
        if (ar[q][k] < maxr)    
        {
            state = 0;
            break;
        }   

        if (ar[q][k] > maxr)
        {
            r = k;
            state = 1;
            continue;
        }
        if (ar[q][k] == maxr)
        {
            state = 1;
            continue;
        }
    }
    count++;
    if (state == 1)
        printf("The saddle point is (%d), location is [%d][%d]\n", ar[q][k], q, k);
    else
        printf("The %d row does not contain a saddle point\n", count);
}
}

该程序是为寻找鞍点而设计的。二维数组中的鞍点，是指行中最大的点，列中最小的点。例如第一行1、2，第二行3、4，则鞍点为2。

我遇到的问题是，这个程序可以找到3*3数组的鞍点，但无法找到4*4(或更高)数组的鞍点。

例如，

2, 3, 9, 5
6, 7, 8, 3
0, 5, 7, 5
2, 1, 8, 3

那么鞍点就是第3行第3、7列。但是程序找不到。

那么问题出在哪里，是逻辑问题吗？但我可以找到 2*2 或 3*3 数组的鞍点..

Answer 1

您应该在循环内重置 max 值。

这将在每列中找到一个鞍点。

#include <stdio.h>

int main(void){
     int n, m, i, j, k,max;
     puts("Enter two numbers represents two dimensional array, N * M");
     puts("This program will find the saddle points");
     scanf("%d %d", &n, &m);
     int ar[n][m];
     for (j = 0; j < n; j++)            
        for (i = 0; i < m; i++){
            puts("Enter the number in array");
            scanf("%d", &ar[j][i]);     //store the number form user
            printf("Array accepted %d, and this number's location is [%d][%d]\n", ar[i][j], i, j);
        }

    for (j = 0; j < n; j++){ //print the two dimensional array
        for (i = 0; i < m; i++)
           printf("%3d", ar[j][i]);
        putchar('\n');
    }


    for (int i = 0; i < n; i++){ //for each row
        max=0;
        for (j = 1; j < m; j++) //find biggest in the row
            if(ar[i][j] > ar[i][max])     
                max=j;

        for (k=0; k < n; k++)   // if there are bigger element than this in that column, break
            if (ar[k][max] < ar[i][max])    
                break;
        if(k==n)    // if there were no bigger elements in the column
            printf("The saddle point is (%d), location is [%d][%d]\n", ar[i][max], i+1, max+1);        
    }
}