PTA L2-039 Inventory Code Library (STL)

4.18 I just finished the China University Computer Contest-Group Programming Ladder Competition. I participated in the GPLT for the first time, and I was 9 points away from the second place. Ahhh, I am a good dish (QAQ). I should try another question of L3 .

Then if you have time, pick a few questions and post ideas and code

[Problem Description]
First assume that if two functional modules accept the same input and always give the same output, they are functionally repetitive; secondly, we simplify the output of each module to an integer (in int $intrange$ )$.$
So we can design a series of inputs and check the corresponding outputs of all functional modules, so as to find codes with duplicate functions. Your task is to design and implement a solution to this simplified problem.

【Input format】
Input is given in the first line $2$ positive integers, followed by$N$ and$M$ , corresponds to the number of function modules and the number of series test inputs.
Then$N$ lines, each line gives$M$ corresponding outputs, the numbers are separated by spaces.

[Output format]
First output the number $K.$ _
Followed by K lines, each line gives the number of modules with this function, and the corresponding output of this function. Numbers are separated by a space, and there must be no extra spaces at the beginning and end of the line.
The output is first given in non-increasing order of the number of modules, and if there is a tie, it is given in increasing order of the output sequence.
Note: The so-called sequence$A_1,\dots ,A_M$比$B_1,\dots ,B_M$Large, means that there is $1\le i<M$ , use$A_1=B_1,\dots ,A_i=B_i$established, and $A_{i+1}>B_{i+1}$。

【Data range】
$1\le N\le 10^4$
$1\le M\le 100$

【Input sample】

7 3
35 28 74
-1 -1 22
28 74 35
-1 -1 22
11 66 0
35 28 74
35 28 74

【Example of output】

4
3 35 28 74
2 -1 -1 22
1 11 66 0
1 28 74 35

【analyze】

---

This question examines $The\; use\; of\; STL$ , for each set of input data, store itvectorand map it mapto the top$,\; and\; count\; the\; number\; of\; times$$it$ appears. At this time , it has been sorted according to the lexicographical ordermap. vectorThenstoremapeach pair of elementsin , and put the number of occurrences of each group of data in, sinceit is sorted from small to large according to,so you need to add a negative sign before the number of times when storing. Thenjustthe finalresultpairvectorfirstsortpairfirstsort
sort(ans.begin(), ans.end(), greater<pair<int, vector<int> > >());

---

【Code】

#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
#include <map>
using namespace std;

const int N = 10010, M = 110;
map<vector<int>, int> cnt;
vector<pair<int, vector<int> > > ans;
int n, m;

int main()
{
    
    
	scanf("%d%d", &n, &m);
	for (int i = 0; i < n; i++)
	{
    
    
		vector<int> temp;
		for (int j = 0; j < m; j++)
		{
    
    
			int x;
			scanf("%d", &x);
			temp.push_back(x);
		}
		cnt[temp]++;
	}
	for (auto &u : cnt) ans.push_back({
    
     -u.second, u.first });
	//for (auto &[u, v] : cnt) ans.push_back({ -v, u });//C++新特性，PTA不支持
	sort(ans.begin(), ans.end());
	printf("%d\n", cnt.size());
	for (auto &u : ans)
	{
    
    
		printf("%d", -u.first);
		for (auto &v : u.second)
			printf(" %d", v);
		puts("");
	}
	return 0;
}