It looks like this is a web page, not a feed. I looked for a feed associated with this page, but couldn't find one. Please enter the address of your feed to validate.

Source: https://leetcode.com/u/nxhmehkyuqj/

  1. <!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="360"></head><body><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "leetcode.com",cType: 'managed',cRay: '9496484a2f5d81b5',cH: 'AGYSZ9xUPqEblOG34a6M1ypCe_eCpjXaR74Q_fViIWk-1748860299-1.2.1.1-YZsgSiDmXh4a3eWtcwp5rrrchWRYpGg60xVQwc1H.7MYl.YaSb515OClSJH4v.Vq',cUPMDTk: "\/u\/nxhmehkyuqj\/?__cf_chl_tk=unVFdEdL1sq50ftZzXwgj20dSSdvQ0kqV3NODigJsbM-1748860299-1.0.1.1-Mk6aHpwlkzXwADZL2ymlfoPdtAsbrZuEMMVwL5N40UY",cFPWv: 'g',cITimeS: '1748860299',cTplC: 0,cTplV: 5,cTplB: 'cf',fa: "\/u\/nxhmehkyuqj\/?__cf_chl_f_tk=unVFdEdL1sq50ftZzXwgj20dSSdvQ0kqV3NODigJsbM-1748860299-1.0.1.1-Mk6aHpwlkzXwADZL2ymlfoPdtAsbrZuEMMVwL5N40UY",md: "WzhXPq9JLiLemjaEy65fm4q94pnXNEwJVsj7dmmiel8-1748860299-1.2.1.1-skdYLTr4L950W9ZHGSzVBEYt4u6PKRPiun7tKbfSLziYXf_oCrrECfwfLsRjOmp1SnzBh4d0XHpHsoUKygWtJlDfNOIqx62UjzqsROP1I2tArPgp_NfQYgnMKfHXhkrTAhM2PPpKr_suJYj08SHgoBqfAi_ne.BIqzX7whAfjx1ebv1uIQwQBFZsbtWHbYx1JLJpLQqq6IwUPEticJ0J5bZNWBxzmWQdTf6AnuhgEPPVAFwDrq0iYauH5Ri5R9Brc889.aQYsE43EJUf37xUKz1iILvUzacvq.qZR__L9KAXP8xIZ8OihlFNmQZ7eWEOIAgtTt2tOoq9ZQT1ch.MQc6wT6HLc8Tqs.4LbawYE2utgTEvsyAFRY5THcfiu0rAqpSHGIGOyFYh_9PGchGDDb2DTl.pjylpAQHAoYBOQYb8bvN3eYtGgp4Red25yL8PjWf2KBKlF6YuPA4KUttKUC0InPC.xdb8olarjzZNR_L4RHD8KqbDD7qkfDjGs_7qRamV1fQgJqk0HhfwyLHILDBm0AQeTzGNs5Xi8FJU5_nlZRM4e_3AEdmPYtp3WcLq_sDCe3d6eL5cKvNefkfXa80oVrwVyIGypu7IQgAK8mnumYk9t1MrS5PZiIpwJKjCTAl.mfw47CRU6ecRbpLeDItQOO5DlIhL.UA.VgYj07lh7hajoB0Vt_l3fELYPiP0GEC6FEgnOS9J3Lx8iFEe9cu.7cMlfvZIFMb.Cb.CcI4gJTQethjLmqcDopTKANkydq.jjTRbtE4cprAinRUWul5tQkVMlcabfBvbLS1GL4QHyQhGSvn9ntOEVrTdWoiynuI8m8WYJs.lCzjX1GHpkUgWWbirb6bqJ0PUv4OM9PPUi4z0u2058scKuCNXwA71eRQ0NcAoxeX.KbO5zMwjr9v_8EYiSLPdblAj5mQF5UE",mdrd: "C5bDb2._PnPep70hS46t8PTaUJiw1fSYZW9se4TRsPI-1748860299-1.2.1.1-4mR_1QQ5JBro3VH2fxlWWeA.NGbQkpdtSYhOzs2cQUR8c8fzrpuDAtTKrwosG.x.Pn1g.kU3mDJEbipuZLxqhJaVky_Ea95fQZNFQu6tVnTL9dzoAxHbTWeQoJusyRK7TNJMDQy1_dM5jjfoSM2GYz491mWLdayCcZiEo6mwJUdi24EiH8BBdqY.iO7Kzgy_xHEoWJltT.gF7sYdOGgV9m5MdjsQGZ9qU__7EkELjGBIFPOMTESMxZlac.rtNZoYw1pAyC0s4bhmhgTzjJV_siSSJczs7VM65AIcgxQaBZFIpJkZXQc7BXGoT7myhMbMsTpv6ymCzcUp3b0qdklLlzCIaHT5bQ6m8zc.GY3IzcXzNWZG94kSejytiQFMoqj2B1.8aW7WiR1e7PJlQkBLFvGWRxWRsTOmX2sombd93V4jspf0fVi6BLaJtFlNxJLsy94wzU_2Ofy3J_g8NE3sbirtTaXUK5G.2FBHQ6SPOKA0KCsR6Mx.AStBxFV1Ce3_7vGJ3RANKQEpRz6Ws8K1FG_eNC.SLwgzEc.twausUwSGluwMfJXGU_mAHOCr4UgLZynEtlFF7YC1YRo5LanSpDm5Ss1yp_ewcsfKaSRAhlFvg2qJ.FQt8MvYy.fmtV7zoh2ME5orbPUn.9fQuwdOs89Sg0Cs_.woItP4fnk.b_dLTQ6XvCe6Ij90EHkauTAthRzb..mBz7uJu0QaNPZ9iUICIsxxJQa080M6HZXQicTA.7P9XdRiJZvx6ldKtvj1MrcyuXzsYzjaeEdD.ChK4NTucW4uTx_.4hSp4q.ngFzgumcT48T.OxHYONSZzp7gmt1SYJTpkIF8uN.RQqMK7aivtKO5KWVO2n0zWnIYQFUXMs.ttT3tz6Yyysi7o1QXm9NCDzHevRcrReEN0QIiN4mNIcnxrVQ3BoRablvu_IC2MWEiGVDP.DZ8OiDz8hOVt41IOAW7NpWPQma2naKIpxXf_TVBSqQyIglS4W0rlyZteVgf.7vgknp_nkX.6T0pl.cshywxQTUhzsok8GndBIgtA2WGN4X.yoPxAvvEIPjOTcJMyb_Ei9TPzPNtTvz2yv22yWPgccNd5_DF7iWKjg4aXGwMhQlhoiALJXIK8uwPL24gc5VUpHoEiJy_ZC82hq2ni8evmpxLIIy4PanRseHyxeZ4_Unz6DBhBuYMi.UfCjPWTGpLt7M4SX6uJWbFa6WBjP5j5DGXcyD6GLADWTRdlUGeimyLr4LpgndfnT76jAQHlQHGNSME3RFvqnxm4_t7YXbkdI.A4cWNU0hAvdDDe6kT4CJrpQ7Y2vKlpEvnlbbKL3L2qegbhUkNW.K9TyBVXPBDvv90QuVt9WYSpgPKxl0olSjBHiwqLZGloQK3EUErnApJ6JryUye3yaUhVjr3qi2QNhdrDHF16RBangZFaRMF866.2mYtSr1YZ_g9o7sToVf8mjpCwUdjG.fiyiWmkyYEYsClaT5iipT.C0ppRUQEwnSu6xEjDCwDKkYBuV0briyg6XgZBYjspSrjRmQ59YL7S7Ws68xjW5N84JSWYkxOoaL1AIaQBvkfXSSuTkbkay8lYC4ekQKm6TXni7_pMyr1sbzg4LeZylPKqM2Y1x0RNkS4jt.MZeJqcHMyFcLloucuWmqEx2EzmcmvXSrrf1MWGrFnzpW._NF9YZT.H3rNbfeiA5pADkYmD4EUnN9aBOe.fvOIlG2VQQmZvCGx0GmQbOlkyArkGCwuPuHWMDi46jmyauK6vF9oJRs73KfUevZ_dN0uLis2AFxzDw5Hb7OlCYtdve5tYdFEP12mfyli4OzvI9UR8mzx_uRPQLZm0HNZb6bcTG9tJ3639hgURZlF_lSiDAPwDlwPuQ"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=9496484a2f5d81b5';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/u\/nxhmehkyuqj\/?__cf_chl_rt_tk=unVFdEdL1sq50ftZzXwgj20dSSdvQ0kqV3NODigJsbM-1748860299-1.0.1.1-Mk6aHpwlkzXwADZL2ymlfoPdtAsbrZuEMMVwL5N40UY" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>
Copyright © 2002-9 Sam Ruby, Mark Pilgrim, Joseph Walton, and Phil Ringnalda