Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Sort the Matrix Diagonally in C++
Suppose we have N x M matrix, we have to sort this diagonally in increasing order from top-left to the bottom right. So if the matrix is like −
| 3 | 3 | 1 | 1 |
| 2 | 2 | 1 | 2 |
| 1 | 1 | 1 | 2 |
The output matrix will be −
| 1 | 1 | 1 | 1 |
| 1 | 2 | 2 | 2 |
| 1 | 2 | 3 | 3 |
To solve this, we will follow these steps −
Define a method called solve(), this will take si, sj and matrix mat
n := number of rows and m := number of columns
make an array called temp
i:= si and j := sj, and index := 0
while i < n and j < m
insert m[i, j] into temp, then increase i and j by 1
sort temp array
set index := 0, i := si and j := sj
while i < n and j < m
mat[i, j] := temp[index]
increase i, j and index by 1
from the main method, do the following −
n := number of rows and m := number of columns
for i in range 0 to n – 1
solve(i, 0, mat)
for j in range 1 to m – 1
solve(0, j, mat)
return mat
Example (C++)
Let us see the following implementation to get a better understanding −
#include <bits/stdc++.h>
using namespace std;
void print_vector(vector<vector<auto> > v){
cout << "[";
for(int i = 0; i<v.size(); i++){
cout << "[";
for(int j = 0; j <v[i].size(); j++){
cout << v[i][j] << ", ";
}
cout << "],";
}
cout << "]"<<endl;
}
class Solution {
public:
void solve(int si, int sj, vector < vector <int> > &mat){
int n = mat.size();
int m = mat[0].size();
vector <int> temp;
int i = si;
int j = sj;
int idx = 0;
while(i < n && j < m){
temp.push_back(mat[i][j]);
i++;
j++;
}
sort(temp.begin(), temp.end());
idx = 0;
i = si;
j = sj;
while(i < n && j < m){
mat[i][j] = temp[idx];
i++;
j++;
idx++;
}
}
vector<vector<int>> diagonalSort(vector<vector<int>>& mat) {
int n = mat.size();
int m = mat[0].size();
for(int i = 0; i <n; i++){
solve(i, 0, mat);
}
for(int j = 1; j < m; j++){
solve(0, j, mat);
}
return mat;
}
};
main(){
vector<vector<int>> v = {{3,3,1,1},{2,2,1,2},{1,1,1,2}};
Solution ob;
print_vector(ob.diagonalSort(v));
}Input
[[3,3,1,1],[2,2,1,2],[1,1,1,2]]
Output
[[1,1,1,1],[1,2,2,2],[1,2,3,3]]
264 Views
