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{"managingGroups":{},"author":"TreeZeng","updateTime":1523609580000,"title":"我运行没错。为何检测我错了?","dislikeCnt":0,"content":"```\n//对于表达式n^2+n+41,当n在(x,y)范围内取整数值时(包括x,y)(-39\u003c\u003dx\u003cy\u003c\u003d50),\n//判定该表达式的值是否都为素数。\nimport java.util.Scanner;\nimport java.lang.Math;\n\npublic class Prime_expression{\n\tpublic static void main(String args[]){\n\t\t\n\t\tScanner reader \u003d new Scanner(System.in);\n\t\twhile(true){\n\t\t\tSystem.out.print(\"给我数x,按下回车键确认: \");//输入x和y\n\t\t\tint x \u003d reader.nextInt();\n\t\t\tSystem.out.print(\"给我数y,按下回车键确认: \");\n\t\t\tint y \u003d reader.nextInt();\n\t\t\t\n\t\t\tif ( x \u003d\u003d y ){\t\t\t\t\t\t\t\t\t//交换位置\n\t\t\t\tif( x \u003d\u003d 0 ){\n\t\t\t\tbreak;\n\t\t\t\t}\n\t\t\t}\n\t\t\t\n\t\t\tif (y \u003c x){\t\n\t\t\t\tint temp \u003d x;\n\t\t\t\tx \u003d y;\n\t\t\t\ty \u003d temp;\n\t\t\t}\t\t\t\n\t\t\t//通过表达式求出要判断的值![](http://)\n\t\t\tboolean flag \u003d false;\n\t\t\tSystem.out.println(x + \" \"+y);\n\t\t\t\n\t\t\t for(;x \u003c\u003d y ;x++){\n\t\t\t\tflag \u003d isnot_prime(x*x + x +41);\n\t\t\t\tif(!flag){\n\t\t\t\t\tSystem.out.println(\"Sorry\");\n\t\t\t\t\tbreak;\n\t\t\t\t}\t\t\t\n\t\t\t}\n\t\t\tif (flag){\n\t\t\t\tSystem.out.println(\"OK\");\n\t\t\t}\n\t\t}\n\t\t//如果全是输出Ok,否则输出sorry \n\t\t\n\t\tSystem.out.println(\"程序已结束\");\t\n\t}\n\tpublic static boolean isnot_prime(int x ){\n\t\t\n\t\tfor(int i \u003d 2;i\u003c\u003d Math.sqrt(x);i++){\n\t\t\tif (x % i \u003d\u003d 0){\n\t\t\t\treturn false;\n\t\t\t}\t\t\n\t\t}\n\t\treturn true;\n\t}\n}![](http://)\n```","threadId":27957,"likeCnt":3,"createTime":1523609580000,"isWorkbook":false,"viewCnt":2923,"openness":2,"fav":false,"id":403,"trustable":false}