2980번: 도로와 신호등

#include <stdio.h>

int main()

{

int N, L, D, R, G, sec = 0, m = 0, lastD = 0;

scanf("%d %d", &N, &L);

for (int i = 0, cooltime; i < N; ++i)

{

scanf("%d %d %d", &D, &R, &G);

sec += (D - lastD);

m += (D - lastD);

cooltime = sec % (R + G);

sec = (cooltime <= R) ? sec + (R - cooltime) : sec;

lastD = D;

}

printf("%d", sec + (L - m));

}