结构体类型数组int成员变量求和函数

struct stru1{ int a; float b; int c; int d;};struct stru2{ int a; char b[100]; int c; stru1 d;};struct stru1 s1[100];struct stru2 s2[100];...int sum1 = supersumofint(&s1[0].c, 100, sizeof(stru1));int sum2 = supersumofint(&s2[0].d.d, 100, sizeof(stru2));int supersumofint(const int *iptr, int n, int strulen){ int i; int sum; if (n & 1)  {   sum = *iptr;   ((const char *)iptr) += strulen;   i = 1;  } else  {   sum = 0;   i = 0;  } for ( ; i < n; i += 2)  {   sum += *iptr;   ((const char *)iptr) += strulen;   sum += *iptr;   ((const char *)iptr) += strulen;  } return sum;}