C :

#include <stdio.h>
#include <stdlib.h>

#define MAXSIZE 12500//矩阵的最大值
#define MAXRC 100//行或列的最大值

//定义三元组矩阵存储元素类型
typedef struct
{
	int x, y;//x为行号，y为列号
	int e;//e为数值
}Triple;

void zhuanzhi()
{
	Triple san[100];
	Triple san1[100];
	int tu, nu, mu;//tu代表行数，nu代表列数，mu代表非零元个数

	scanf("%d%d%d", &tu, &nu, &mu);

	for (int i = 0; i < mu; i++)
		scanf("%d%d%d", &san[i].x, &san[i].y, &san[i].e);

	int k = 0;
	for (int i = 1; i <= nu; i++)
	{
		for (int j = 0; j < mu; j++)
		{
			if (san[j].y == i)
			{
				san1[k].x = san[j].y;
				san1[k].y = san[j].x;
				san1[k].e = san[j].e;
				k++;
			}
		}
		
	}
	for (int k = 0; k < mu; k++)
	{
		printf("%d %d %d\n", san1[k].x, san1[k].y, san1[k].e);
	}
}

int main()
{
	int n;
	scanf("%d", &n);
	for (int i = 0; i < n;i++)
	{
		zhuanzhi();
		if (i < n - 1)
			printf("\n");
	}
	return 0;
}

C++ :

#include<stdio.h>
#include <algorithm>
using namespace std; 
typedef struct node
{
	int x,y,wei;
};
int cmp(const node& a,const node & b)
{
	return (a.x<b.x||(a.x==b.x&&a.y<b.y));
}
int main()
{
	int t;scanf("%d",&t);
	int dd=0;
	while(t--)
	{
		if (dd==1) printf("\n");
		else dd=1;
		node k[20];
		int a,b,c;scanf("%d%d%d",&a,&b,&c);
		for (int i=0;i<c;i++)
			scanf("%d%d%d",&k[i].y,&k[i].x,&k[i].wei);
		sort(k,k+c,cmp);
		for (int i=0;i<c;i++)
			printf("%d %d %d\n",k[i].x,k[i].y,k[i].wei);
	}
	return 0;
}