refine the lottery algorithm to reduce its computational complexity
Fork of app_board-Lottery by
main.cpp
- Committer:
- wuulong
- Date:
- 2016-07-20
- Revision:
- 0:e0789676dfe5
- Child:
- 1:c9dba148697b
File content as of revision 0:e0789676dfe5:
/** README: The Lottery toy that used in LASS Users and Developers conference. Each run will generate GIFT_MAXCNT non-repeat number, random range ( 1 to MAN_MAXCNT ) */ #include "mbed.h" #include "C12832.h" C12832 lcd(p5, p7, p6, p8, p11); DigitalIn fire(p14); BusOut leds(LED1,LED2,LED3,LED4); AnalogIn RandomIn(p17); // use the random noise on this analog input to seed the random generator #define GIFT_MAXCNT 24 // Max gift count #define MAN_MAXCNT 120 // How many users void SetLed(uint8_t ledID, bool on) { if (ledID <= 6) { if (on) leds = leds | (0x01 << ledID); else leds = leds & ~(0x01 << ledID); } } void SweepAllLeds(bool leftToRight, float delay) { leds=0; wait(delay); for(int n=0; n<4; n++) { rand(); SetLed(leftToRight?n:4-n, true); wait(delay); // delay } } int main() { int gift[GIFT_MAXCNT]; lcd.cls(); lcd.locate(0,3); lcd.printf("LASS Conference"); lcd.locate(0,15); lcd.printf("Lottery 1-120"); while (!fire) { // After botton pressed, generate random seed SweepAllLeds(true,0.01); uint32_t seedValue = 0; uint16_t value; uint8_t counter; for (counter = 0; counter < 32; counter++) { seedValue = seedValue<<1; value = RandomIn.read_u16(); // reads a 10 bit ADC normalised to 16 bits. if (value & 0x0040) // LSB of ADC output is a 1 seedValue++; } srand(seedValue); } // show some UI to feel like Lottery lcd.cls(); lcd.locate(0,3); lcd.printf("Begin Lottery..."); SweepAllLeds(true,0.1); SweepAllLeds(true,0.1); SweepAllLeds(true,0.1); SweepAllLeds(true,0.1); float twait=(rand()%10)/10; wait(twait); lcd.locate(0,3); lcd.cls(); // Generate non-repeat users for(int i=0;i<GIFT_MAXCNT;i++){ while(1){ int rand_num = rand()%MAN_MAXCNT; int repeat=0; for(int j=0;j<i;j++){ if( gift[j] == rand_num ) repeat=1; } if(repeat==0){ gift[i] = rand_num; break; } } } // Show the results on LCD for(int i=0;i<GIFT_MAXCNT;i++){ int x=(i % 8)*16; int y = int(i/8)*10; lcd.locate(x,y); lcd.printf("%3d", gift[i]); } }