class Main {
    public static void main(String[] args) {
        show(18);
    }

    private static void show(int n) {
        String tmp = "";
        for (int i = 1; i <= n; i++) {
            // int 转 string
            tmp = String.valueOf(i);
            // 打印包含1的整数
            if (tmp.contains("1")) {
                System.out.print(i + ", ");
            }
        }
    }
}

------解决方案--------------------

contains()
最终最终依靠的是这个函数
Java code

    static int indexOf(char[] source, int sourceOffset, int sourceCount,
                       char[] target, int targetOffset, int targetCount,
                       int fromIndex) {
    if (fromIndex >= sourceCount) {
            return (targetCount == 0 ? sourceCount : -1);
    }
        if (fromIndex < 0) {
            fromIndex = 0;
        }
    if (targetCount == 0) {
        return fromIndex;
    }

        char first  = target[targetOffset];
        int max = sourceOffset + (sourceCount - targetCount);

        for (int i = sourceOffset + fromIndex; i <= max; i++) {
            /* Look for first character. */
            if (source[i] != first) {
                while (++i <= max && source[i] != first);
            }

            /* Found first character, now look at the rest of v2 */
            if (i <= max) {
                int j = i + 1;
                int end = j + targetCount - 1;
                for (int k = targetOffset + 1; j < end && source[j] ==
                         target[k]; j++, k++);

                if (j == end) {
                    /* Found whole string. */
                    return i - sourceOffset;
                }
            }
        }
        return -1;
    }