//Sample09_01.java class Sample09_01{ public static void main(String[] args){ StringBuilder sb = new StringBuilder(); sb.append("黄瀬涼太\n"); sb.append("緑間真太郎\n"); sb.append("青峰大輝\n"); sb.append("紫原敦\n"); sb.append("赤司征十郎\n"); System.out.println(sb.toString()); System.out.println("-----------------"); String searchWord = "\n"; int rowNo = 1; int offset = 0; sb.insert(offset, rowNo + "\t"); rowNo++; offset = sb.indexOf(searchWord, offset); while(offset != -1){ offset += searchWord.length(); if(offset >= sb.length())break; sb.insert(offset, rowNo + "\t"); rowNo++; offset = sb.indexOf(searchWord, offset); } System.out.println(sb.toString()); System.out.println("-----------------"); sb.insert(0, "NO\t氏名\n"); System.out.println(sb.toString()); } }