给定长度的空格分割字符串

//以空格分割的字符串读入
char str[30][5] = { 0 };
    int num[30] = { 0 };
    char graph[30] = { 0 };
    int n,i,j,max,row;
    int flag = 1;
    cin >> n;
    for (i = 0; i < n; i++) {
        scanf("%s", str[i]);// cin>>str[i];
    }