# File format
5 10 # Number of dimensions, size of each dimension
1 2 3 4 5 6 7 ... # Data

int numDim, dimSize;
// Read number of dimensions, size of each dimension
char* data = (char*) malloc(sizeof(char) * numDim * dimSize);

for (int i = 0; i < numDim; ++i) {
    for (int j = 0; j < dimSize; ++j) {
        data[i * dimSize + j] = read character from file;
    }
}