\u00a0\u9898\u76ee\u5927\u610f
\nBessie \u5728\u8dd1\u6b65，\u603b\u5171\u6709 $K$ \u7c73，\u4e00\u5f00\u59cb\u901f\u5ea6\u4e3a $0$，\u6bcf\u79d2\u949f\u53ef\u4ee5\u5c06\u901f\u5ea6\u589e\u52a0 $1$ \u7c73\u6bcf\u79d2，\u6216\u8005\u51cf\u5c11 $1$ \u7c73\u6bcf\u79d2，\u6216\u8005\u901f\u5ea6\u4e0d\u53d8\u3002\u5e76\u8981\u6c42\u5230\u8fbe\u7ec8\u70b9\u65f6\u7684\u901f\u5ea6\u4e0d\u8d85\u8fc7 $X$ \u7c73\u6bcf\u79d2，\u95ee\u6700\u5c11\u8981\u82b1\u591a\u5c11\u65f6\u95f4\u3002<\/p>\n
\u7b97\u6cd5\u7b5b\u9009
\n1. \u4e00\u5f00\u59cb\u60f3\u5230\u8d2a\u5fc3，\u53ef\u4e0d\u77e5\u9053\u4ec0\u4e48\u65f6\u5019\u5f00\u59cb\u964d\u901f，\u4e0d\u53ef\u53d6\u3002
\n2. \u63a5\u4e0b\u6765\u60f3\u4e00\u4e0b\u52a8\u6001\u89c4\u5212，\u53ef\u662f\u6570\u636e\u8303\u56f4\u8f83\u5927，\u6570\u7ec4\u5f00\u4e0d\u4e0b，\u4e0d\u53ef\u53d6\u3002
\n3. \u4e8c\u5206，\u8c8c\u4f3c\u770b\u8d77\u6765\u6ca1\u4ec0\u4e48\u95ee\u9898，\u5224\u65ad\u662f\u5426\u6709\u5355\u8c03\u6027，\u53ea\u8981\u65f6\u95f4\u7ed9\u7684\u591f\u591a\u90a3\u8fbe\u6210\u9898\u76ee\u8981\u6c42\u7684\u51e0\u7387\u5c31\u4f1a\u66f4\u5927，\u5355\u8c03\u6027\u4e5f\u6709\u4e86，\u6240\u4ee5\u91c7\u7528\u4e8c\u5206\u89e3\u51b3\u672c\u9898\u3002<\/p>\n
\u901f\u5ea6\u53d8\u5316\u8f68\u8ff9
\n\u5f88\u7b80\u5355\u7684\u8d2a\u5fc3，\u6211\u4eec\u60f3\u8ba9\u65f6\u95f4\u5c3d\u53ef\u80fd\u5c11\u5c31\u8bf4\u660e\u60f3\u8ba9\u901f\u5ea6\u5c3d\u53ef\u80fd\u5feb，\u4f46\u8981\u6ee1\u8db3\u5230\u8fbe\u7ec8\u70b9\u65f6\u901f\u5ea6\u4e0d\u8d85\u8fc7 $X$ \u7c73\u6bcf\u79d2，\u6240\u4ee5\u53d8\u5316\u8f68\u8ff9\u662f\u4e00\u4e2a\u68af\u5f62\u6216\u8005\u4e00\u4e2a\u4e09\u89d2\u5f62，\u68af\u5f62\u7684\u4e0a\u5e95\u662f\u901f\u5ea6\u6700\u5feb\u7684\u90e8\u5206，\u5de6\u8fb9\u7684\u8170\u662f\u901f\u5ea6\u5728\u4e0a\u5347\u7684\u90e8\u5206，\u53f3\u8fb9\u7684\u8170\u662f\u901f\u5ea6\u5728\u4e0b\u964d\u7684\u90e8\u5206\u3002\u4e09\u89d2\u5f62\u5c31\u662f\u5c06\u901f\u5ea6\u6700\u5feb\u7684\u90e8\u5206\u7684\u65f6\u95f4\u88ab\u8feb\u538b\u7f29\u5230\u4e86 $1$\u3002<\/p>\n
\u5224\u65ad\u662f\u5426\u5408\u6cd5
\n\u5224\u65ad\u7b54\u6848\u662f\u5426\u5408\u6cd5\u662f\u4e8c\u5206\u4e2d\u975e\u5e38\u91cd\u8981\u7684\u73af\u8282，\u6211\u4eec\u5206\u4e3a\u4e24\u4e2a\u5927\u7c7b\u8ba8\u8bba\u3002<\/p>\n
1. \u6211\u4eec\u8bbe\u4e8c\u5206\u5230\u7684\u7b54\u6848\u662f $mid$，\u8fd9\u79cd\u60c5\u51b5\u662f\u4e0d\u7ba1\u600e\u4e48\u52a0\u901f\u6700\u540e\u90fd\u8d85\u4e0d\u8fc7 $X$\u3002\u4e5f\u5c31\u662f $mid \\\\le X$ \u7684\u60c5\u51b5，\u56e0\u4e3a\u6bcf\u79d2\u949f\u6700\u591a\u53ea\u80fd\u63d0\u5347 $1$ \u7c73\u6bcf\u79d2\u3002
\n2. \u6b63\u5e38\u60c5\u51b5，\u5c31\u662f\u5728\u901f\u5ea6\u53d8\u5316\u8f68\u8ff9\u4e2d\u8bf4\u5230\u7684\u60c5\u51b5，\u73b0\u5728\u53ea\u9700\u8981\u6c42\u51fa\u5728\u6574\u4e2a\u8fd0\u52a8\u8fc7\u7a0b\u4e2d\u7684\u6700\u5927\u901f\u5ea6\u662f\u591a\u5c11\u5c31\u53ef\u4ee5\u4e86\u3002\u6211\u4eec\u8bbe\u6700\u5927\u901f\u5ea6\u4e3a $x$，\u5c31\u53ef\u4ee5\u5f97\u5230\u4ee5\u4e0b\u7684\u65b9\u7a0b\u3002
\n3.
\n$$
\nx + x – mid + 1 = t
\n$$<\/p>\n
$$
\nx = \\\\frac{t+mid-1}{2}
\n$$<\/p>\n
\u8be5\u8ba1\u7b97\u8ddd\u79bb，\u56e0\u4e3a\u6bcf\u79d2\u901f\u5ea6\u6700\u591a\u53ea\u80fd\u53d8\u5316 $1$，\u73b0\u5728\u5c31\u6210\u4e86\u51e0\u4e2a\u7b49\u5dee\u6570\u5217\u7ec4\u6210，\u901a\u8fc7\u7b97\u51fa\u7684 $x$ \u8f85\u52a9\u5206\u5c42，\u56e0\u4e3a $x$ \u5728\u68af\u5f62\u6216\u4e09\u89d2\u5f62\u7684\u9876\u7aef\u6240\u4ee5\u901a\u8fc7\u627e\u51fa\u901f\u5ea6\u4e3a $x$ \u7c73\u6bcf\u79d2\u7684\u8ddd\u79bb\u7684\u5de6\u7aef\u70b9\u548c\u53f3\u7aef\u70b9\u4f5c\u4e3a\u4e34\u754c\u70b9\u5373\u53ef\u5b8c\u6210\u5206\u5c42，\u518d\u4f7f\u7528\u7b49\u5dee\u6570\u5217\u6c42\u548c\u516c\u5f0f\u8ba1\u7b97\u5c31\u53ef\u4ee5\u7b97\u51fa\u5728\u65f6\u95f4\u4e3a $mid$ \u79d2\u65f6\u6700\u591a\u53ef\u4ee5\u8dd1\u591a\u5c11\u7684\u8ddd\u79bb\u3002\u5982\u679c\u8ddd\u79bb\u6ee1\u8db3\u8981\u6c42\u8bb0\u5f55\u7b54\u6848\u5e76\u5bfb\u627e\u66f4\u4f18\u89e3，\u5426\u5219\u5c06 $mid$ \u8c03\u5927\u3002<\/p>\n
## \u5173\u952e\u4ee3\u7801<\/p>\n
bool check(int z,int t){
\n\u00a0\u00a0 \u00a0if(z<=t){\/\/\u7b2c1\u79cd\u60c5\u51b5
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0if(((z+1)*z)\/2>=k){
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0return true;
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0}
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0else{
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0return false;
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0}
\n\u00a0\u00a0 \u00a0}
\n\u00a0\u00a0 \u00a0int s=(z+t)\/2;
\n\u00a0\u00a0 \u00a0int ss=0;\/\/\u7528\u4e8e\u5b58\u50a8\u8ddd\u79bb
\n\u00a0\u00a0 \u00a0if((z+t)%2==1){
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0ss+=cmp(1,s);\/\/cmp\u7528\u4e8e\u5904\u74061~s\u7684\u7b49\u5dee\u5e8f\u5217\u6c42\u548c
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0ss+=cmp(s,t);
\n\u00a0\u00a0 \u00a0}
\n\u00a0\u00a0 \u00a0else{
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0ss+=cmp(1,s);
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0ss+=cmp(s-1,t);
\n\u00a0\u00a0 \u00a0}
\n\u00a0\u00a0 \u00a0if(ss>=k){\/\/\u5224\u65ad\u662f\u5426\u5408\u6cd5
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0return true;\/\/\u6ee1\u8db3\u6761\u4ef6
\n\u00a0\u00a0 \u00a0}
\n\u00a0\u00a0 \u00a0else{
\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0return false;\/\/\u4e0d\u6ee1\u8db3
\n\u00a0\u00a0 \u00a0}
\n}<\/p>\n","protected":false},"excerpt":{"rendered":"
\u9898\u76ee\u5927\u610f
\nBessie \u5728\u8dd1\u6b65，\u603b\u5171\u6709 $K$ \u7c73，\u4e00\u5f00\u59cb\u901f\u5ea6\u4e3a $0$，\u6bcf\u79d2\u949f\u53ef\u4ee5\u5c06\u901f\u5ea6\u589e\u52a0 $1$ \u7c73\u6bcf\u79d2，\u6216\u8005\u51cf\u5c11 $1$ \u7c73\u6bcf\u79d2，\u6216\u8005\u901f\u5ea6\u4e0d\u53d8\u3002\u5e76\u8981\u6c42\u5230\u8fbe\u7ec8\u70b9\u65f6\u7684\u901f\u5ea6\u4e0d\u8d85\u8fc7 $X$ \u7c73\u6bcf\u79d2，\u95ee\u6700\u5c11\u8981\u82b1\u591a\u5c11\u65f6\u95f4\u3002\u7b97\u6cd5\u7b5b\u9009
\n1. \u4e00\u5f00\u59cb\u60f3\u5230\u8d2a\u5fc3，\u53ef\u4e0d\u77e5\u9053\u4ec0\u4e48\u65f6\u5019\u5f00\u59cb\u964d\u901f，\u4e0d\u53ef\u53d6\u3002
\n2. \u63a5\u4e0b\u6765\u60f3\u4e00\u4e0b\u52a8\u6001\u89c4\u5212，\u53ef\u662f\u6570\u636e\u8303\u56f4\u8f83\u5927，\u6570\u7ec4\u5f00\u4e0d<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[55],"topic":[],"class_list":["post-75282","post","type-post","status-publish","format-standard","hentry","category-server","tag-c"],"yoast_head":"\n