1、while语句
#include <stdio.h>
int main(void) { int i, sum = 0; puts("please input an integer."); do { printf("i = "); scanf("%d", &i); if (i <= 0) puts("the range of i is: > 0. "); } while (i <= 0); printf("the sum of 1 to %d is: ", i); while (i > 0) { sum += i; i--; } printf("%d\n", sum); return 0; }
2、while语句；
#include <stdio.h>
int main(void) { int i = 1, j, sum = 0; puts("please input an integer."); do { printf("j = "); scanf("%d", &j); if (j <= 0) puts("the range of j is: > 0 "); } while (j <= 0); printf("the sum of 1 to %d is: ", j); while (i <= j) { sum += i; i++; } printf("%d\n", sum); return 0; }
3、for语句
#include <stdio.h>
int main(void) { int i, sum = 0; puts("please input an integer."); do { printf("i = "); scanf("%d", &i); if (i <= 0) puts("the range of i is : > 0 "); } while (i <= 0 ); printf("the sum of 1 to %d is: ", i); for (i; i > 0; i--) { sum += i; } printf("%d\n", sum ); return 0; }
4、for语句
#include <stdio.h>
int main(void) { int i, j, sum = 0; puts("please input an integer."); do { printf("j = "); scanf("%d", &j); if (j <= 0) puts("the range of j is: > 0. "); } while (j <= 0); printf("the sum of 1 to %d is: ", j); for (i = 1; i <= j; i++) { sum += i; } printf("%d\n", sum); return 0; }
5、do语句
#include <stdio.h>
int main(void) { int i, sum = 0; puts("please input an integer."); do { printf("i = "); scanf("%d", &i); if (i <= 0) puts("the range of i is: > 0 "); } while (i <= 0); printf("the sum of 1 to %d is: ", i); do { sum += i; i--; } while (i > 0); printf("%d\n", sum); return 0; }
6、do语句
#include <stdio.h>
int main(void) { int i = 1, j, sum = 0; puts("please input an integer."); do { printf("j = "); scanf("%d", &j); if (j <= 0) puts("the range of j is: > 0 "); } while (j <= 0); printf("the sum of 1 to %d is: ", j); do { sum += i; i++; } while (i <= j); printf("%d\n", sum); return 0; }