Begin end cbegin cend crbegin crend

#1

whats the difference in all these vector functions
im not able to get it through cplusplus refernce,
pls make it clear in a simple language

#2

begin: it gives you an iterator which contains value of address of begining element.
end: it gives you an iterator which contains value of address of end element.

cbegin it gives you an constant iterator which contain value of address of begining element
cend: it gives you an constant iterator which contain value of address of end element

constant iterator means Iterator cannot modify the contents of the vector. it is used only for printing

#3

whats crbegin and crend

#4

rbegin means it will give reverse iterator contains value of last element .
reverse iterator means on increasing iterator it will move back.
for ex vector contains 11 12 13 14 15
for (auto it = v.rbegin(); it != v.rend(); it++)
cout << *it << " ";
it will print
15 14 13 12 11

rend returns a reverse iterator pointing to the theoretical element right before the first element in the array container. it is always use with rbegin as done above

i hope u understand if yes then hit a like

#5

#include
#include
using namespace std;
int main() {
int n, m;
cin >> n >> m;
vector < vector> v(m);

for (int i = 0;i < n;i++) {
	for (int j = 0;j < m;j++) {
		int temp;
		cin >> temp;
		v[i].push_back(temp);
	}
}
for (int i = 0;i < v.size();i++) {

for (auto it = v[i].begin();it != v[i].end();–it) {
cout << *it << ", ";
}
}
}

#6

whats wrong in that above code

#7

#include
#include
using namespace std;
int main() {
int n, m;
cin >> n >> m;
vector < vector> v(m);

for (int i = 0;i < n;i++) {
for (int j = 0;j < m;j++) {
int temp;
cin >> temp;
v[i].push_back(temp);
}
}
for(auto it:v){
for(auto element:it){
cout<<element<<" ";
}
cout<<endl;
}

/*for (auto i = 0;i < v.size();i++) {

for (auto it = v[i].begin();it != v[i].end();–it) {
cout << it << ", ";
}
}*/
return 0;
}

use for each loop