0ms runtime C++ solution
```\n\nclass Solution {\npublic:\n    int numberOfRounds(string s, string f) {\n        string h = "", m = "", h1 = "", m1 = "";\n        int j, count = 0;\n   
```\n\nclass Solution {\npublic:\n    int numberOfRounds(string s, string f) {\n        string h = "", m = "", h1 = "", m1 = "";\n        int j, count = 0;\n        for(int i = 0; i<s.length(); i++){\n            if(s[i]==\':\'){j = i;break;}\n            h+=s[i];\n        }\n        for(int i = j+1; i<s.length(); i++){\n            m+=s[i];\n        }\n        for(int i = 0; i<f.length(); i++){\n            if(f[i]==\':\'){j = i;break;}\n            h1+=f[i];\n        }\n        for(int i = j+1; i<f.length(); i++){\n            m1+=f[i];\n        }\n        string d = "00";\n        if(!m.compare(d)&&!m1.compare(d)){\n            int l = stoi(h);\n            int e = stoi(h1);\n            if(e<l){\n                e+=24;\n                return(4*(e-l));\n            }else{return(4*(e-l));}\n        }if(m.compare(d)!=0){\n            int l = 60 - stoi(m);\n            int e = l/15;\n            count+=e;\n            if(m1.compare(d)!=0){\n                int z = stoi(m1)-0;\n                count+=(z/15);\n                int n = stoi(h);\n                int o = stoi(h1);\n                if(o<n){\n                    o+=24;\n                    count+=4*(o-1 - (n));\n                }else if(o==n){\n                    if(stoi(m1)<stoi(m)){\n                        o+=24;\n                        count+=4*(o-1 - (n));\n                    }else{\n                      if(stoi(m1)%15==0||stoi(m)%15==0){\n                          count = (stoi(m1) - stoi(m))/15;\n                      }\n                        else{\n                            if(stoi(m1) - stoi(m)<15){count=0;}\n                            else{\n                               int y = stoi(m);\n                                while(y%15!=0){y++;}\n                                count = (stoi(m1) - y)/15;\n                            }\n                            \n                        }\n                      \n                    }\n                    \n                }\n                else{\n                    count+=4*(o-1 - (n));\n                }\n            }else{\n                int n = stoi(h);\n                int o = stoi(h1);\n                 if(o<n){\n                    o+=24;\n                    count+=4*(o-1 - (n));\n                }else if(o==n){\n                    if(stoi(m1)<stoi(m)){\n                        o+=24;\n                        count+=4*(o-1 - (n));\n                    }else{\n                      count+=4*(o-1 - (n));  \n                    }\n                    \n                }\n                else{\n                    count+=4*(o-1-(n));\n                }\n            }\n        }\n      else if(m1.compare(d)!=0){\n            int l = stoi(m1)-0;\n            int e = l/15;\n            count+=e;\n            if(m.compare(d)!=0){\n                int z = stoi(m)-0;\n                count+=(z/15);\n                int n = stoi(h);\n                int o = stoi(h1);\n                 if(o<n){\n                    o+=24;\n                    count+=4*(o-1 - (n));\n                }else if(o==n){\n                    if(stoi(m1)<stoi(m)){\n                        o+=24;\n                        count+=4*(o-1 - (n));\n                    }else{\n                      count+=4*(o-1 - (n));  \n                    }\n                    \n                }\n                else{\n                    count+=4*(o-1 - n);\n                }\n            }else{\n                int n = stoi(h);\n                int o = stoi(h1);\n                 if(o<n){\n                    o+=24;\n                    count+=4*(o - (n));\n                }else if(o==n){\n                    if(stoi(m1)<stoi(m)){\n                        o+=24;\n                        count+=4*(o - (n));\n                    }else{\n                        \n                      count+=4*(o - (n));  \n                    }\n                    \n                }else{\n                     \n                     count+=4*(o - (n));\n                 }\n            }\n        }\n        return count;\n    }\n};
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