_Find_first() function in C++ bitset with Examples
The _Find_first() is a built-in function in C++ Biteset class which returns an integer that refers the position of first set bit in bitset. If there isn’t any set bit, _Find_first() will return the size of the bitset.
Syntax:
iterator bitset._Find_first()
or
int bitset._Find_first()
Parameters: The function accepts no parameter.
Return Value: The function returns an integer which refers to the position of first set bit in bitset. If there isn’t any set bit, _Find_first() will return the size of the bitset.
Below is the illustration of the above function:
// C++ program for illustration// of _Find_first() function #include <bits/stdc++.h>using namespace std; #define M 32 int main(){ // default constructor initializes with all bits 0 bitset<M> bset; bitset<M> bset1; // 00000000000000000000000000100000 bset[5] = 1; // 00000000000000000000010000100000 bset[10] = 1; // function returns the first set bit in Bitset cout << "position of first set bit in bset\n"; cout << bset._Find_first() << "\n"; // function returns bset1.size() // when no bit is set in bitset. cout << "position of first set bit in bset1\n"; cout << bset1._Find_first() << "\n"; return 0;} |
Output:
position of first set bit in bset 5 position of first set bit in bset1 32
Reference: https://gcc.gnu.org/onlinedocs/libstdc++/libstdc++-html-USERS-3.4/bitset-source.html
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