C语言算法问题，求大神解答，给出代码？

#includestdio.h#includestring.hvoid main(){char s[100] = "I AM A STUDENT";char t[100]="GOOD";char q[100]="WORKER";printf("%d %d %s %s",strlenth(s), strlength(t), substring(s,8,7), substring(t,2,1));printf("%s %s %s", index(s,"A"), index(s,t), concat(substring(s,6,2),concat(t,substring(s,7,7)))); }