c++matrixmultidimensional-arraydynamic-programmingbottom-up

Cant initialize a 2d array/matrix to 0

I am trying to initialize a 2d array (matrix) to 0 but, cant do it:

int longestCommonSubsequence(string text1, string text2) {
    int len1=0;
    len1=text1.length()+1;
    int len2=0;
    len2=text2.length()+1;
    int dp[len1][len2]={0};

Error:

Line 8: Char 16: error: variable-sized object may not be initialized
        int dp[len1][len2]={0};
               ^~~~
1 error generated.

I want initialize the matrix while declaring it. I do not want to use for loop.

Solution

  • Variable sized arrays are not standard C++, for arrays of constant length you just use value-initialisation syntax:

    int arr[4][4]{};

    Alternatively, use C++ collections of variable length:

    int rows = 4;
int columns = 4;
std::vector<std::vector<int>> vec(rows, std::vector<int>(columns));