C конвертируйте строку в size_t
char string[] = "1234"; // The string you want to convert to size_t.
size_t i;
sscanf(string, "%zu", &i);
// i == 1234
Yvant2000
char string[] = "1234"; // The string you want to convert to size_t.
size_t i;
sscanf(string, "%zu", &i);
// i == 1234