1.求一个3X3整型矩阵对角线元素之和
#include<stdio.h> int main() { int a[3][3] = { { 1,2,3 },{ 4,5,6 },{ 7,8,9 } }; int i, j, sum = 0; for (i = 0; i<3; i++) { for (j = 0; j<3; j++) { if (i == j || i + j == 2) { sum += a[i][j]; } } } printf("%d\n", sum); return 0; }
2.有一篇文章,共有3行文字,每行有80个字符。分别统计出大写字母、小写字母、数字、空格以及其他字符的个数
#include<stdio.h> #include<string.h> int main() { int capitalletter = 0, lowerletter = 0, space = 0, number = 0, other = 0, i, j; char text[3][80]; for (i = 0; i<3; i++) { printf("please input line %d:\n", i + 1); gets_s(text[i]); for (j = 0; j<80 && text[i][j] != '\0'; j++) { if (text[i][j] >= 'A'&& text[i][j] <= 'Z') capitalletter++; else if (text[i][j] >= 'a' && text[i][j] <= 'z') lowerletter++; else if (text[i][j] >= '0' && text[i][j] <= '9') number++; else if (text[i][j] == ' ') space++; else other++; } } printf("capitalletter=%d\nlowerletter=%d\nspace=%d\nnumber=%d\nother=%d\n", capitalletter, lowerletter,space, number, other); return 0; }
3.编一程序,将两个字符串连接起来,不用strcat函数
#include<stdio.h> #include<string.h> int main() { char c1[80], c2[80]; int i, j; printf("Input string1:"); gets_s(c1); printf("Input string2:"); gets_s(c2); for (j = 0, i = strlen(c1); c2[j] != '\0'; i++, j++) c1[i] = c2[j]; c1[i] = '\0'; puts(c1); return 0; }