ABC296A判断字符串是否字母交替

#include <stdio.h>
int n, m, i, j, k;
char c, p, s[105]; 
int main(){
    scanf("%d%s", &n, s);
    for(i=0; c=s[i]; i++){
        if(c == p) break;
        p = c;//相邻不相同即交替
    }
    printf("%s\n", c?"No":"Yes");
    return 0;
}