hiho_1061_beautiful_string

题目大意

    题目连接:beautiful string 
    写代码之前,考虑清楚流程,以及需要维护的变量....

实现

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#include<iostream>
#include<stdio.h>
#include<string.h>
#include<stack>
#include<vector>
#include<unordered_set>
#include<unordered_map>
using namespace std;
char str[10 * 1024 * 1024 + 2];
int main(){
    int T;
    scanf("%d", &T);
    while (T--){
        int n;
        scanf("%d", &n);
        getchar();
        scanf("%s", str);      
        int i = 0;
        bool valid = false;
        int beg = 0, end = 0;
        int count_1 = 0; //前2个字符连续的个数
        int count_2 = 0; //前1个字符连续的个数
        while (beg < n && !valid){
            char cur = str[beg]; //当前字符
            while (end < n && !valid){
                if (str[end] == cur){                  
                    //如果前两个字符都有,且当前字符数目大于等于中间字符数目,
                    //则肯定可以形成一个valid的子串
                    if (count_2 && count_1 && end - beg + 1 >= count_2){
                        valid = true;
                        break;
                    }
                    end++;
                }
                else{
                    if (str[end] - cur != 1){//出现了一个不连续字符,则清空count_1,count_2
                        count_1 = 0;
                        count_2 = 0;
                    }
                    else{                      
                        //当前字符之前的那个字符的连续个数大于count_2的个数,
                        //则只能以当前字符作为新的中间字符 count_2,且
                        //count_1 清空
                        if (count_2 && count_2 < end - beg){
                            count_1 = 0;
                            count_2 = end - beg;
                        }
                        else{
                            //更新count_1 为count_2
                            //更新 count_2为 end-beg;
                            count_1 = count_2;
                            count_2 = end - beg;
                        }                      
                    }
                    break;
                }
            }
            beg = end;
        }
        if (valid)
            printf("YES\n");
        else
            printf("NO\n");
    }
    return 0;
}

 

posted @   农民伯伯-Coding  阅读(228)  评论(0)    收藏  举报
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