int strangeGrid(int r, int c) { // Base value for the row group (each pair of rows increases base by 10) int base = (r - 1) / 2 * 10;

// Check if the row is odd or even
if (r % 2 == 1) {
    // Odd row: Start at base, increment by 2 for each column
    return base + (c - 1) * 2;
} else {
    // Even row: Start at base + 1, increment by 2 for each column
    return base + 1 + (c - 1) * 2;
}

}

cpp code:

long long strangeGrid(long long r,long long c) { long long result = 0;

if (r % 2 != 0) {
    result = (r - 1) * 5 + (c - 1) * 2;  
} 
else {
    result = (r - 2) * 5 + (c - 1) * 2 + 1;
}

return result;

}

A solution template for Java is wrong. You should change the return type from int to long,

return r % 2 == 0 ? (10*(r/2 - 1) + 1) + (2*c - 2) : 10*((r+1)/2 - 1) + 2*(c-1)

or

return r % 2 == 0 ? 5*r - 11 + 2*c : 5*r - 7 + 2*c

for c++ must convertt the parsing of int to long long variable and also change stoi() to stoll() i got accepted after this