c语言打印乘法口诀和三角

打印乘法口诀和三角所用的算法跟java一样,直接上代码

打印乘法口诀:

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#include <stdio.h>
int main(void)
{
for (int i = 1; i <= 9; ++i) {
for (int j = 1; j <= i; ++j) {
printf("%d*%d=%d\t", j, i, i*j);
}
printf("\n");
}
return 0;
}

//执行结果:
1*1=1
1*2=2 2*2=4
1*3=3 2*3=6 3*3=9
1*4=4 2*4=8 3*4=12 4*4=16
1*5=5 2*5=10 3*5=15 4*5=20 5*5=25
1*6=6 2*6=12 3*6=18 4*6=24 5*6=30 6*6=36
1*7=7 2*7=14 3*7=21 4*7=28 5*7=35 6*7=42 7*7=49
1*8=8 2*8=16 3*8=24 4*8=32 5*8=40 6*8=48 7*8=56 8*8=64
1*9=9 2*9=18 3*9=27 4*9=36 5*9=45 6*9=54 7*9=63 8*9=72 9*9=81

三角,同时输出两个三角,一正一倒:

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#include <stdio.h>
int main(void)
{
/* 正-倒
* 1-9
* 3-7
* 5-5
* 7-3
* 9-1 */
for (int i = 1; i <= 9; ++i) {
if ( i % 2 != 0) {
for (int j = 1; j <= (9-i)/2; ++j) {
printf("%c", ' ');
}
for (int j = 1; j <= i; ++j) {
printf("%c", '*');
}
for (int j = 1; j<=(9-i)/2; ++j) {
printf("%c", ' ');
}

printf("\t");

for (int j = 1; j<= (9-(10-i))/2; ++j) {
printf("%c", ' ');
}
for (int j = 1; j<= (10-i); ++j) {
printf("%c", '*');
}
for (int j = 1; j<= (9-(10-i))/2; ++j) {
printf("%c", ' ');
}

printf("\n");
}
}
return 0;
}

//执行结果:
* *********
*** *******
***** *****
******* ***
********* *