c用while循环打印三角形,直角,空心直角,等腰,等腰空心

直角三角形 t1.c 

#include

main() {
        int i,j;
        i=1;
        while (i<=10) {
                j=1;
                while (j<=i) {
                        printf("*");
                        j++;
                }

                printf("\n");
                i++;
        }
}

直角空心三角形 t2.c

#include

main() {
        int i,j;
        i=1;
        while (i<=10) {
                j=1;
                while (j<=i) {
                        if (j==1 || j==i || i==10)
                                printf("*");
                        else
                                printf(" ");
                        j++;
                }

                printf("\n");
                i++;
        }
}

等腰三角形 t3.c

#include

main() {
        int i,j;
        i=1;
        while (i<=10) {
                j=1;
                while (j<=10-i) {
                        printf(" ");
                        j++;
                }
                j=1;
                while (j<=(2*i-1)) {
                        printf("*");
                        j++;
                }

                printf("\n");
                i++;
        }
}

等腰空心三角形 t4.c

#include

main() {
        int i,j;
        i=1;
        while (i<=10) {
                j=1;
                while (j<=10-i) {
                        printf(" ");
                        j++;
                }
                j=1;
                while (j<=(2*i-1)) {
                        if (j==1 || j==(2*i-1) || i==10)
                                printf("*");
                        else
                                printf(" ");
                        j++;
                }

                printf("\n");
                i++;
        }
}