python solution with sliding window
\n\nclass Solution:\n    def equalSubstring(self, s: str, t: str, maxCost: int) -> int:\n        if maxCost == 0 and s!=t:\n            return 1\n        res = 
\n```\nclass Solution:\n    def equalSubstring(self, s: str, t: str, maxCost: int) -> int:\n        if maxCost == 0 and s!=t:\n            return 1\n        res = 0\n        m={\'a\':1,\'b\':2,\'c\':3,\'d\':4,\'e\':5,\'f\':6,\'g\':7,\'h\':8,\'i\':9,\'j\':10,\'k\':11,\'l\':12,\'m\':13,\'n\':14,\'o\':15,\'p\':16,\'q\':17,\'r\':18,\'s\':19,\'t\':20,\'u\':21,\'v\':22,\'w\':23,\'x\':24,\'y\':25,\'z\':26}\n        l1=[]\n        l2=[]\n        for k in range(len(s)):\n            l1.append(m[s[k]])\n            l2.append(m[t[k]])\n        l = 0\n        for r in range(len(s)):\n            maxCost -= (abs(l2[r]-l1[r]))\n            if maxCost < 0:\n                maxCost += (abs(l2[l]-l1[l]))\n                l += 1\n        return r-l+1\n            \n```\n
['Sliding Window', 'Python']