最长单词（计数定位）

#include<bits/stdc++.h>
using namespace std;
int main(){
    string a;
    getline(cin, a);
    int l = a.length();

    int max = 0, currentmax = 0;
    int index = 0;

    for(int i = 0; i < l; i++){
        if((a[i] >= 'a' && a[i] <= 'z' )|| (a[i] >= 'A' && a[i] <= 'Z' )){
            currentmax ++;}
        else{currentmax = 0;}

        if(currentmax > max){
            max = currentmax;
            index = i;
        }
    }

    string result = a.substr(index - max + 1, max);

    cout << result;


    return 0;
}