c++ simple solution  (0ms)
\nclass Solution {\npublic:\n    string modifyString(string s) \n    {\n        int n=s.size();\n        for(int i=0;i<n;i++)\n        {\n            if(s[i]==\
```\nclass Solution {\npublic:\n    string modifyString(string s) \n    {\n        int n=s.size();\n        for(int i=0;i<n;i++)\n        {\n            if(s[i]==\'?\')\n            {\n                s[i]=\'a\';\n                while(((i>0)&&(s[i-1]==s[i]))||(i+1<n&&(s[i+1]==s[i])))\n                {\n                    s[i]++;\n                }\n            }\n        }\n        return s;\n    }\n};\n```
[]